NEW YORK—If today's men's semifinals are even half as good as last night's semis on the women's side, we're in for a treat. Reporting from Arthur Ashe Stadium, Ed McGrogan is live blogging both matches: Alexander Zverev  vs. Pablo Carreno Busta , followed by Dominic Thiem  vs. Daniil Medvedev . The winners will compete for their first Grand Slam title on Sunday.
Final, Second Match: Thiem wins 6-2, 7-6 (7), 7-6 (5)
"It's all or nothing," Dominic Thiem told ESPN's Patrick McEnroe, about a US Open final in which the Austrian will try to avoid losing his first four appearances in a Grand Slam title match. "If I win I have my first; if not, I'll have to call Andy Murray, see how it is with that 0-4."
Thiem's wit was as quick as his turnarounds in the second and third sets of a match that was anything but a proverbial "straight-setter." Medvedev could easily be leading Thiem two sets to one right now, if not for the No. 2 seed's timely pushes—as in the second set, he broke Medvedev to stay in the set—combined with bold play in the tiebreakers.
In this tiebreaker, Thiem was ahead from the start, with leads of 4-0 and 5-1. If it seemed too easy against a player like Medvedev, it was. At 5-2, Medvedev carved an impeccable stab volley that gave Thiem something to think about:
Soon, Thiem's lead was down to 5-4, on serve. What followed was one of the best rallies of the match, a series of haymakers that both men threw and defended with aplomb. But the one that landed, and would set the stage for the knockout punch, was Thiem's signature backhand. He cracked it down the line—it was going to end the exchange, one way or another—and it stayed in, giving him two match points.
He'd need them both, but he didn't throw away his shot.
First and Second Set, Second Match: Thiem leads, 6-2, 7-6 (7)
After a straightforward first set, the second featured more of the give-and-take we expected from these two sublime shotmakers.
But by the end of it, you have to wonder if Thiem had taken the life out of Medvedev.
The Russian served for the second set at 5-4, but was broken. He appeared on the verge of getting the advantage back, but Thiem saved all five break points at 5-5. Commendably, Medvedev held serve to force a tiebreaker, but it would only lead to more frustration.
First, Medvedev had a set point wiped away by a flawless Thiem serve out wide. There was nothing he could do about it; two points later, Medvedev did the same thing to Thiem.
But the point played in between those set points is one Medvedev would love to have back. Again, Medvedev found himself in an advantageous position, but again, Thiem escaped.
As quirky as Medvedev can be, he can power through a forehand if he elects to. At 6-6, after detonating two crosscourt forehands and accentuating them with vocal grunts, he had a third forehand, this of the inside-out variety to the opposite corner. But he overcooked it, and offered his opponent new life.
While Thiem wasn't able to sew up the set until his second chance, it feels like an opportunity lost for Medvedev. As such, a semifinal being played at a much higher competitiveness than the previous match may end earlier than fans would hope.
Two other notes:
—In the first set, Medvedev tried to challenge his own serve, but he wasn't granted his wish after the umpire said he had already hit his next shot. After a heated exchange of words, Medvedev was warned for crossing the next to look at the mark—then went on another tirade with a tournament official in the corner of the court.
Daniil Medvedev just received a warning for crossing the net to point at a mark after he wasn't allowed to challenge late. After discussion with umpire and supervisor, a very sarcastic: "My sincere apologies to US Open for crossing the net."— Tumaini Carayol (@tumcarayol) September 12, 2020
Watch for yourself:
EARLY DRAMA! ????????— SBS Sport (@SBSSport) September 12, 2020
Medvedev BLOWS UP at the umpire, and gets a warning for his trouble! ????
???? WATCH ???????? @ThiemDomi v ???????? @DaniilMedwed in the @usopen semi-final LIVE on @SBS and @SBSOnDemand right NOW! ???????? #sbstennis #USOpen
????: https://t.co/aINb2BCktM pic.twitter.com/ixjUexfSFP
—After Thiem won the second set, he received treatment on his ankle.
Final, First Match: Zverev wins 3-6, 2-6, 6-3, 6-4, 6-3
Some five-setters are epics. Some are rollercoasters. Some are dramatic. This five-setter was none of those things.
But that was just fine for Alexander Zverev, who continued his breakthrough season by reaching his first career Grand Slam final. The German made the final four at a major for the first time at January's Australian Open, and eight months later, with the world a completely different place, he's into his first title match at the sport's highest level.
Another first: this is Zverev's first comeback win from two sets down.
Alexander the Great indeed. ????@AlexZverev comes back from two sets down to reach his first Grand Slam final, also becoming the youngest Grand Slam finalist since Djokovic at the 2010 US Open.— Tennis Channel (@TennisChannel) September 11, 2020
Live blog → https://t.co/navPamCOe1#USOpen pic.twitter.com/6EApSHTYEo
Like the Serena Williams-Sloane Stephens third-rounder, this match was an example of two players playing well at completely different times. From the moment the third set began, Zverev suddenly found his first serve, cleaned up his game and let Carreno Busta self-combust in exchanges. The Spaniard took a medical timeout at the end of the fourth set, but he didn't exhibit any noticeable signs of strain.
In the final game of the match, Zverev raced to another quick lead on serve. While Carreno Busta saved one match point with a forehand winner, it was his last stand—though he never really recovered from his initial knockdown.
I penciled in 5 hours, but Zverev gets it done in a brisk 3:22. Strange match, to say the least, but he finished strong. "I'm into my first Grand Slam final, and that's all that matters," Zverev says.— Steve Tignor (@SteveTignor) September 11, 2020
Next up for Sascha: Dominic Thiem or Daniil Medvedev, fellow Top 10 players looking for their first major trophy.
Fifth Set, First Match: Zverev leads 4-3
It's shocking how drastically Zverev has turned around his serve.
After breaking Carreno Busta in the opening game of the final set, Zverev is racking up routine holds. In the third, fourth and part of the fifth sets, he's won 83, 88 and 87 percent of his first-serve points, respectively.
Now, will Zverev be able to serve so effectively when the pressure begins to mount as the finish line draws near? That's why we watch.
Fourth Set, First Match: Zverev wins 6-4, and improbably forces a decider
Down, but not out. With Carreno Busta serving at 3-3, Zverev took a body blow from the ball while at the net. It would be one of just two points the Spaniard won that game, as Zverev proceeded to win one of the match's longest rallies, and broke for a second time in the set.
An exceedingly comfortable hold followed, and the roles of this match have quickly been reversed. Zverev has tidied up his serve, is drawing errors from Carreno Busta, and looks nothing like the downtrodden player of a few hours' earlier.
Of the energy that exists in Arthur Ashe Stadium, it's all on Sascha's side. His player box is responding to nearly each point he wins—Allez! often accompanies a clap—with Zverev responding just as they hope.
While Zverev let three set points go at 5-3, 0-40 he went on to hold—capped with an ace—to send this semi to a fifth. (Also, Zverev was hit with another ball from Carreno Busta. He didn't like that.)
Of more significance: Carreno Busta has taken a medical timeout between sets.
Hmm. Zverev has been on the receiving end of two Carreno Busta shots, and he didn't like the second one.— Ed McGrogan (@EdMcGrogan) September 11, 2020
In the first game Sascha was struck, he broke serve. In the second, he let four set points slip (from 0-40).
He'll serve for a decider. #USOpen pic.twitter.com/k3qh9W7dQ9
Third Set, First Match: Zverev gets on the board, 6-3
With nowhere to go but up, Zverev began what he hopes is a long climb back with a pair of breaks, taking advantage of his opponent's leakier play. His serve, a liability during the first two sets, was transformed: Zverev won 10 of 12 points on first serves and 7 of 9 on seconds.
And Carreno Busta's downward trend appears to be continuing: he's down a break in the fourth, 1-2, with seven unforced errors already.
Just 2:15 has elapsed on an a pleasant, humidity-free afternoon in Flushing Meadows. If this goes five, both men will have plenty of gas left.
First and Second Set, First Match: Carreno Busta leads 6-3, 6-2
Before 2020, the knock on Zverev at the majors was that he struggled in the early rounds and didn't have enough left in the tank to make a deep run. The German countered that at this year's Australian Open, not dropping a set through four rounds and reaching his first Grand Slam semifinal. The 23-year-old hasn't been made to go the distance in his five matches in New York, but only one win could be considered straightforward, a 6-2, 6-2, 6-1 fourth-round victory over Alejando Davidovich Fokina.
So how to explain Zverev's performance this far? Physically, he looks fine, but he hasn't moved with the intensity needed to trouble Carreno Busta, nor has he been clean when he's had looks. After two sets, Zverev had won just seven of 30 second-serve points (23%) and had struck 36 unforced errors (against 25 winners).
Keeping Zverev on the defensive for much of the match with heavy forehands, Carreno Busta led both sets by a double break; in the second, he broke Zverev three times to lead 5-0. Zverev broke back once each time, but with no energy to harness in the arena and facing pair of huge deficits, he could only recover so much.
Zverev has been his own worst enemy, but the opponent has inflicted plenty of pain, too.
(For his part, Carreno Busta has won two five-setters—in his first match, and his last match—which sandwiched a pair of straight-sets wins and a default victory. You might remember that one.)