Sinner had won the pair’s only previous meeting just a few weeks ago—a 6-3, 6-3, 4-6, 6-3 fourth-round upset at Roland Garros—and things looked headed the same direction early on in their rematch. The Italian teenager broke serve in the fourth game and then held for a 4-1 lead in the first set.
But Zverev clawed back this time, winning the next four games in a row—he was broken twice while serving for the set at 5-4 and 6-5, but then cruised through the tie-break to take a one-set lead. He then jumped out to an early 3-0 lead in the second set and never really looked back, as the two held serve from there until Zverev had the victory after an hour and 48 minutes on court.
"I was playing a player I had just lost to at Roland Garros, and that was still in the back of my head," Zverev said in his on-court interview after the match. "I was not going to lose today."
Zverev is through to the final in Cologne for the second straight week, having won the title last week. The German city is hosting two straight 250-level events as part of the ATP’s revised fall schedule.
This is the third time Zverev has reached finals in back-to-back weeks. He did it in Washington D.C. and Montreal in the summer of 2017, winning both titles, and then three weeks in a row in the clay court season in 2018, winning Munich and Madrid but finishing runner-up in Rome to Rafael Nadal.
The German has a 12-8 career record in ATP finals.
Awaiting the No. 1-seeded Zverev in the final will be the No. 2 seed, Diego Schwartzman, who won a two-hour, 31-minute battle with No. 5 seed Felix Auger-Aliassime in the second semifinal, 6-4, 5-7, 6-4. Schwartzman originally served for the match at 6-4, 5-4 before the Canadian pushed it to a third.
Zverev and Schwartzman have played three times before and Schwartzman leads, 2-1. They're 1-1 on hard courts, the Argentine winning their last meeting at the 2019 US Open, 3-6, 6-2, 6-4, 6-3, but the German winning their only indoor hard-court meeting at the Masters 1000 in Paris in 2018, 6-4, 6-2.
"He is the undefeated man [in Cologne] so far," Schwartzman told ATPTour.com. "Maybe tomorrow is the first match he is going to lose. I don't know. He is a great player. He always likes to play in Germany. He has won a lot of titles here in his country, so it is going to be very tough.
"He has confidence and he's playing very good tennis, so I have to rest and be ready for tomorrow."
Schwartzman, who's playing his first tournament as a Top 10 player, has a 3-6 record in ATP finals.