No. 16 Tommy Robredo defeats Jack Sock 7-6 (5), 6-3
Philipp Kohlschreiber defeats Jeremy Chardy 6-3, 4-6, 6-4
Yen-Hsun Lu defeats Denis Istomin 6-3, 6-4
Benjamin Becker defeats Ivo Karlovic 7-6 (5), 6-4
Fernando Verdasco defeats Marcel Granollers 5-7, 6-3, 7-6 (5)
Marinko Matosevic defeats Nicolas Mahut 6-4, 7-6 (4)
Gael Monfils defeats Federico Delbonis 6-3, 3-6, 6-3
Gilles Simon defeats Bernard Tomic 6-3, 6-2
Jerzy Janowicz defeats Teymuraz Gabashvili 6-4, 6-4
Joao Sousa defeats Chase Buchanan 5-7, 7-6 (3), 7-6 (5)
No. 11 John Isner defeats Kevin Anderson 6-3, 6-4
Fabio Fognini defeats Edouard Roger-Vasselin 6-4, 4-6, 7-6 (5)
Shuai Zhang defeats Heather Watson 6-3, 2-6, 7-5
Elina Svitolina defeats Lauren Davis 6-3, 6-2
Kirsten Flipkens defeats Polona Hercog 6-3, 6-1
Taylor Townsend defeats Klara Koukalova 6-3, 4-6, 7-5
Madison Keys defeats Alize Cornet 6-2, 6-4
Pauline Parmentier defeats Casey Dellacqua 7-6 (4), 6-2
Karin Knapp defeats Belinda Bencic 6-2, 7-6 (1)
Caroline Wozniacki defeats Magdalena Rybarikova 6-2, 6-3
Ana Ivanovic defeats Sorana Cirstea 6-1, 7-5
Anastasia Pavlyuchenkova defeats Dominika Cibulkova 6-3, 6-3
Flavia Pennetta defeats Chanelle Scheepers 6-3, 6-7 (3), 6-2
Samantha Stosur defeats Varvara Lepchenko 6-2, 7-5
In early action, one of the American hopes on the men's side of the draw saw an early exit as Jack Sock was dispatched by 16th-seeded Tommy Robredo in straight sets. Robredo dominated in his service game and Sock didn't have nearly the same success when he initiated points.
By keeping 70 percent of his first serves inbounds and winning 77 percent of the points off his first serve, Robredo kept Sock on his heels. With Sock eliminated, there are now five American men remaining in the draw.
Philipp Kohlschreiber dropped a set to Frenchman Jeremy Chardy before finishing him off in three sets. Kohlschreiber is hoping to gear up for a strong performance at the U.S. Open. He's never advanced beyond the round of 32 in any previous attempts.
Yen-Hsun Lu made quick work of Denis Istomin on Monday. In fact, the match took just over 54 minutes to complete. Lu won 93 percent of his first-service points to keep complete control of the match.
Benjamin Becker had little issue with Ivo Karlovic as well. Despite 17 aces from the 6'11" Karlovic, Becker broke him twice to pull the minor upset. It was the first time in seven meetings Becker was able to beat Karlovic.
Fernando Verdasco needed nearly three hours to take care of his countryman Marcel Granollers on Monday. After dropping the first set, Verdasco stormed back to dominate the second set, and outlasted Granollers through a tiebreaker in the third.
Verdasco's big serve was the life and nearly the death of his game. While he did manage eight aces, his 16 double faults made the win much tougher to come by.
Marinko Matosevic became the second male qualifier to advance on Monday. He followed Becker's lead and won his match over Nicolas Mahut by almost the exact same score as the German's triumph over Karlovic.
Even though Matosevic wasn't pushed to a third set, both of the sets the two men played were competitive. The stats were almost identical in total service and return points, but Matosevic had a four and three-point edge, respectively.
France's most entertaining player Gael Monfils handed Federico Delbonis a loss in just over 90 minutes. Monfils did drop the second set, but the 27-year-old veteran came through in the third set to secure the victory.
Gilles Simon followed his countryman Monfils' lead with a win over qualifier Bernard Tomic. Despite coming up with high expectations, Tomic has never been able to live up to his potential. He continues to struggle as he was never really in the match against Simon. Not once did Tomic have an opportunity to break Simon's serve. This was a pretty easy win for the 29-year-old from Nice.
Jerzy Janowicz couldn't rely on his dominant serve as much as he would have liked against Teymuraz Gabashvili. The 6'8" big server from Poland had nine double faults, but he was still able to capture 87 percent of the points off his first serve.
Gabashvili could never really establish enough rhythm to break through.
In one of the day's most exciting matches, Joao Sousa took down American qualifier Chase Buchanan in three sets. After dropping the first frame, the 25-year-old from Portugal leaned on his big serve to win the final two sets in tiebreakers. Sousa had a total of 15 aces, which was the most of any player on either side of the draw on Monday.
On the women's side, the early action rendered mixed results for the Americans as well.
It took Shuai Zhang three sets to knock off British qualifier Heather Watson. While Watson played well in certain stages of her game, her inaccurate serve was most problematic. Eight double faults cost her dearly, and that thwarted her mild upset attempt.
American qualifier Taylor Townsend bounced back from losing the second set to win a hard-fought third frame against Klara Koukalova. The match took over two hours. With such a physically taxing match taking place so early in the tournament, it's possible that Townsend could be fatigued in subsequent matches.
Madison Keys was the other American woman who was victorious on the tournament's first day of action. She downed tough French contender Alize Cornet in straight sets.
Keys took advantage of eight opportunities to break Cornet's serve. The American was successful four times, and that was the difference in the match.
In another straight-sets win, Kirsten Flipkens easily defeated Polona Hercog. With neither woman boasting a dominant serve, Flipkens was able to go on the offensive in her return game. She broke Hercog five times en route to the win.
Lauren Davis was another American woman making an early exit..
Elina Svitolina was too much for Davis. Again, the break points were the major difference in the match. Davis squandered four opportunities to break Svitolina, while the 19-year-old Ukrainian broke the American four times.
Townsend wasn't the only qualifier to advance on Monday. Pauline Parmentier defeated Australian veteran Casey Dellacqua in straight sets. The Aussie could only managed to keep half of her first serves in bounds, and that made her service game extremely vulnerable.
Parmentier didn't waste many of her opportunities to seize control of points, games, sets and subsequently the match. She broke Dellacqua five times in seven opportunities.
Karin Knapp kept the qualifier success rolling with a straight-sets win over Belinda Bencic that looked similar to Parmentier's win.
There was a definite difference in the fact that Knapp's serve gave Bencic problems all day. Though she double faulted five times, her seven aces kept Bencic off balance.
The No. 13 seed Flavia Pennetta avoided a mild upset from South African qualifier Chanelle Scheepers. After winning the first set, Scheepers rallied to take the second set in a tiebreak. Pennetta easily won the third set to advance.
After her ex-fiancee Rory McIlroy won his third-straight tournament and the fourth major of his career, Caroline Wozniacki came through with a win of her won over Magdaelna Rybarikova in straight sets.
Rybarikova put up little resistance for the No. 12 seed from Denmark.
After a dominant performance in the first set, Ana Ivanovic had some issues with Sorana Cirstea in the second set. The No. 9 seed had to pull out a tight win in the last frame as she ate up Cirstea's weak service game.
In the entire match, Cirstea only managed to win 24 points off her serve.
In perhaps the biggest upset of the day, No. 11 seed Dominika Cibulkova fell to Anastasia Pavlyuchenkova in straight sets. Cibulkova is not a big server, but the fact that she won just 20 of 48 possible points off her serve proves that part of her game was below standard on Monday.
The match took only 1:05:48 seconds to complete.
John Isner, the top American in the tournament, handled Kevin Anderson in straight sets. Interestingly, their last matchup went to three tiebreaker sets, so this was something of a surprise. Isner was able to claim a break in each set and win in 65 minutes.
Fabio Fognini edged past Edouard Roger-Vasselin in one of the most thrilling matches of the day. After exchanging 6-4 victories in the first two sets, Fognini escaped with a victory in a tiebreaker in the final set.
Samantha Stosur rallied in impressive fashion after falling behind 3-5 in the second set. She won four consecutive games to capture a straight-set victory and will now play world No. 1 Serena Williams in her next match.
Match details per Pro Tennis Live.