The American No. 2 scored a fluent win over Robert Kendrick U.S. Men's Clay Court Championships.
Philipp Kohlschreiber upset world No 4 Nikolay Davydenko to put Germany level after Igor Andreev trounced Germany's No 1 Tommy Haas in the opening rubber.
Second seed Tommy Haas and No 3 Marat Safin were ousted from the Washington Open.
Andy Murray overcame an ankle injury and staved off two match points on his way to a 3-6, 6-3, 7-6 victory over Haas in the Pacific Life Open.
Four of Nadal's closest rivals failed to make the last 16, however, as third seed Ivan Ljubicic, fifth seed Nikolay Davydenko, eighth seed James Blake and ninth seed Marcos Baghdatis were upset in their ties.
The top seed will face Kenneth Carlsen in the semi-finals after the unseeded Dane beat American Jan-Michael Gambill at the Kroger St Jude ATP event.
The Serbian's 1-6, 6-3, 6-1 defeat also ended his dream of winning an Olympic singles gold medal, the only major honour missing from his long list of accolades.
World No. 1 Novak Djokovic has applied for special permission to enter the United States to participate in the ATP Masters 1000 events.
It was a routine win for top seed Novak Djokovic, but his satisfaction at reaching the Wimbledon quarter-finals without dropping a set was mixed with relief after some tricky moments against German veteran Tommy Haas on Monday.
The 35-year-old's first match back in action last week at the Stuttgart Open was a flop when he suffered a shock loss to German veteran Tommy Haas, ranked 302 at the time, despite leading for a set and a half.
Roger Federer edged closer to his first title of the season when he came from a set down to beat defending champion Tommy Haas 3-6, 6-3, 6-4 and book a place in Sunday's Halle Open final against Mikhail Youzhny.
World number three and defending champion Roger Federer suffered a surprise defeat in the second round of the Shangahi Masters on Tuesday, losing 7-6(4), 2-6, 6-3 to Spain's Albert Ramos-Vinolas.
Fifth seed Roger Federer was dumped out of the Shanghai Open, losing to Frenchman Gael Monfils 6-4, 6-7(5), 6-3 in the third round on Thursday.
Federer had no regrets about missing the French Open to focus on Wimbledon but said it was a move he was unlikely to repeat.
Novak Djokovic was unexpectedly beaten by fifth-ranked Alexander Zverev, quashing his hopes of winning an Olympic singles gold medal, the only major honour missing from his long list of accolades.
The Frenchman, seeded five, had no answer to left-hander Muller's swinging serve as he bowed out 6-4, 6-4.
Sticking to a limited schedule has helped Roger Federer enjoy a renaissance late in his career but the Swiss says rest time is now over and he is looking forward to returning to action at the Mercedes Cup in Stuttgart.
Top seed Juan Martin del Potro of Argentina took advantage of a long rain delay to defeat Germany's Tommy Haas 7-6(4), 6-3 on Saturday and reach the final of the $1.3 million Citi Open.
The Indian Wells tennis tournament was set to start on Tuesday, attracts the game's top players from both the men's and women's sides and drew a record 475,000 fans over its two-week run last year. It was cancelled over concerns about the spread of a coronavirus in Southern California.
Florian Mayer put more than a year of injury problems behind him to secure a 6-2, 5-7, 6-3 victory over teenager Alexander Zverev in an all-German final at the Halle Open on Sunday.
Rafael Nadal's unprecedented 10th French Open title on Sunday drew praise from across the tennis and sporting community: Here is a selection of what was said:
Novak Djokovic outclassed Finland's Jarkko Nieminen 6-4, 6-2, 6-3 to move safely into the Wimbledon third round on Wednesday.
American qualifier Steve Johnson is through to his first ATP Tour semi-final after an emphatic victory at the Delray Beach Open on Friday.
Federer welcomed the emergence of new challengers
Serbia's Novak Djokovic is the top seed in the men's draw which includes five-times US Open champion and 17-times Grand Slam winner Roger Federer as seventh seed - his first time the Swiss has been placed outside the top three in a Grand Slam in over ten years.
Croatian Marin Cilic continued his recent run of sizzling form by overpowering John Isner 7-6(7-5), 6-3 in a late-night showdown to advance to the Delray Beach Open final against South Africa's Kevin Anderson.
Roger Federer booked his place in the ATP World Tour Finals for a record-tying 12th consecutive year when he dismissed South African Kevin Anderson 6-4, 6-4 to reach the third round of the Paris Masters on Wednesday.
Murray pulled out of the Australian Open on Thursday having failed to recover from the hip injury that had dogged him since the summer of 2017, following his quarter-final exit at Wimbledon in July.
News of all that's transpired on and off the tennis courts.
Nothing that has happened in the past 12 months suggests Roger Federer's hunger is diminished with victory at this year's Australian Open taking his Grand Slam title haul to 20.
Australia's Samantha Stosur failed to allay fears she could be heading for another early exit at her home Grand Slam with a scrappy performance in Hobart while a trio of big names tumbled out of the Sydney International on Monday.
But for the 23-year-old Bouchard, a former world number five who has slumped to 56th in the rankings, it was another blow after her first-round exit in Indian Wells.
Roger Federer got his delayed hardcourt season off to a positive start with straightforward 6-3, 7-6 (7) win over Germany's Phillip Kohlschreiber to ease into the third round of the Western and Southern Open on Tuesday.
Roger Federer and Rafael Nadal have shared the grand slam spoils this year and it would take a hard heart not to hope for a fairy tale rematch next month of their epic 2008 Wimbledon final.
Novak Djokovic, Andy Murray, Rafael Nadal and Roger Federer all picked up third round wins at the Western and Southern Open on Thursday to set up a star-studded last eight in Cincinnati.
Roger Federer has now won all the seven finals he has contested in Cincinnati. Rediff.com takes a look at a few other events that have ensured prolific returns for the Swiss master.
A summary of sports events and persons who made news on Thursday
The lanky wild card kissed the Montreal court after completing a rousing 3-6, 6-4, 7-6(4) triumph as the 18-year-old became the youngest player to ever reach the quarter-finals of an ATP Masters 1000 event.
A summary of sports events and sports persons, who made news on Saturday