In line with 2017, Federer and Djokovic's days took different turns

Day 9 at Wimbledon—men’s quarterfinal day—lived up to the expectations early on Wednesday. Sam Querrey stunned home favorite and top seed Andy Murray in five thrilling sets to become the first American man in a Grand Slam semifinal since 2009.

Shortly thereafter, Marin Cilic ended Gilles Muller’s magical Wimbledon run in another five-setter.

The final two matches, featuring Roger Federer and Novak Djokovic, weren’t quite as compelling, but they certainly came with surprises.

Djokovic, a three-time Wimbledon champion who came into this match having not lost a set at the All England Club, retired with an arm injury trailing 7-6 (2), 2-0. The shocking retirement sent 2010 runner-up Tomas Berdych into his second straight Wimbledon semifinal. The world No. 4 took a medical timeout after dropping the opening set in a tiebreaker, which was particularly concerning considering the 12-time Grand Slam champion’s right shoulder was bothering him the day before.

Tennis Channel recaps the men's quarterfinals on Daily Serve:

The Serb has complained about the courts and the scheduling throughout this fortnight, and this is sure to spark controversy and outrage after Djokovic, unlike his fellow quarterfinalists, was forced to play on consecutive days. Djokovic was scheduled to play Adrian Mannarino on Monday, but the match was postponed until Tuesday when play went long. Instead of moving the match to Centre Court late on Monday, Djokovic had to play his fourth-rounder the following day.

Had Djokovic won this tournament, he would have supplanted Murray as the world No. 1. Murray will now hold onto the top spot.

Tennis Channel's Paul Annacone discusses the player he once coached, Roger Federer:

Federer’s fortunes, as they have been all year, were far better than Djokovic’s on Wednesday. The 18-time Grand Slam champion, in a rematch of last year’s Wimbledon semifinal, defeated Milos Raonic, 6-4, 6-2, 7-6 (4), in fairly straightforward fashion. The seven-time Wimbledon champion, now into his 12th semifinal at the grass-court major, lost to the big-hitting Canadian in the semis last year.

With Murray, Rafael Nadal and Djokovic out of the tournament, Federer is the only member of the Big Four still left standing at the All England Club. He’ll play Berdych in the semifinals, and Cilic will contest Querrey in the other.

—GRAND SLAM WEEK: WatchWimbledon Primetime on Tennis Channel, and catch up on the other 2017 Grand Slams on Tennis Channel Plus

—Watch encores from the 2017 French Open and Australian Open on Tennis Channel Plus, including matches like the AO Final showdown between Serena & Venus Williams**