Gael Monfils was good enough Tuesday to move past No. 7 seed Grigor Dimitrov in a hotly contested match, but he certainly made things interesting.
A glance at the score line -- 7-5, 7-6, 7-5 -- shows just how close this match was, and Monfils nearly self-destructed in the second set. Up a set and a break, Monfils appeared poise to move through easily to the semis. But Dimitrov battled back, leading Monfils to carelessly drop a few games in a row, including one in which he just quit. Down 40-0, Monfils didn't even attempt to return Dimitrov's offering, choosing to stand and the service line and intentionally belt his return wayward.
This did not please the NYC crowd.
But Monfils, somehow, was able to battle back in the set, eventually winning a tiebreak. He went on to win the third, as well, moving into the quarterfinals. Through four rounds at Flushing Meadows, Monfils has yet to drop a set. Pretty impressive for a guy who has only onced reached a Grand Slam semifinal.
The 20th-seeded Monfils will face the winner of Roger Federer and Roberto Bautista Agut.
Peng breezes into semis
Shuai Peng will be making her first career appearance in a Grand Slam semifinals, as she easily dispatched of 17-year-old Belinda Bencic Tuesday, winning 6-2, 6-1.
It was never really close, as Bencic could never quite get things going in the right direction. Peng had 24 winners to only seven unforced errors, while Bencic was far more prone to mishits, committing 19 unforced errors.
Overall, Peng has been surprisingly dominant in her run through the field. She has yet to lose a set -- or even five games in a single set -- and that includes victories over the No. 4 seed Agnieszka Radwanska, No. 28 seed Roberta Vinci, and No. 14 seed Lucie Safarova.
Peng now awaits the winner of Tuesday night's match between Caroline Wozniacki and Sara Errani.
Williams sisters eliminated in doubles
For the second time in two chances, the Russian duo of Elena Vesnina and Ekaterina Makarova have defeated the Williams sisters, this time in the quarterfinals of the US Open Tuesday, 7-6, 6-4.
The Russians started strong, jumping ahead 4-1 in the first set before salting the lead away. They were able to hang on in a tiebreak, and Makarova and Vesnina had an easier time in the second set.
The No. 4 seeds move on the face the winners of Andrea Hlavackova/Jie Zheng and Kimiko Date-Krumm/Barbora Zahlavova Strycova.
There was a brief scare for Serena, as trainers looked ate her right ankle midway through the second set. She appeared to be fine after a short break.
While Serena's quest for a doubles title is over, she's still alive in women's singles, and could face Makarova in the semifinals should both players advance.
Bryan brothers into semis
The top-seeded American duo was pushed by the Spanish duo Fernando Verdasco and David Marrero, but they were able to move on in three sets, 6-2, 4-6, 6-4. The Bryans are in search of their fifth US Open title and 16th Grand Slam overall.
They will face a fellow American, Eric Butorac, along with Russian Raven Klaasen in the semifinals.
A US Open championship would give the Bryans their 100th win as a doubles team.
No. 6 seed Tomas Berdych had little trouble with Dominic Thiem of Austria Tuesday, winning 61, 6-2, 6-4.
Berdych was in control from the start, and he never allowed Thiem to get any sort of control. He held serve throughout while breaking the Austrian five times en route to victory.
Berdych, who is looking to make his second trip to the US Open semis, will face Marin Cilic in the quarterfinal.
Late break seals it for Cilic
The five-setter between Marin Cilic and Gilles Simon was about as close as it could be. But Cilic's break in the fifth set was the difference, and the No. 14 seed moved into the quarterfinal, besting Simon 5-7, 7-6, 6-4, 3-6, 6-3.
Both players managed just three breaks a piece, and the fifth set appeared destined for a second tiebreak. But Cilic was able to win the break and hold serve for the match.
Cilic was by no means great on Tuesday, committing 75 unforced errors to Simon's 31. But he was timely and picked his spots well, hitting 67 winners and moving into his third career US Open quarterfinal, where he will face Tomas Berdych.