Roger Federer and Novak Djokovic raced into the third round with straight sets wins but the day was marred by a horrific knee injury to American Bethanie Mattek-Sands, who was carried off on a stretcher during her singles match at Wimbledon on Thursday.
Seven-time champion Federer turned on the style to beat Serbian Dusan Lajovic 7-6 (0) 6-3 6-2, while Djokovic needed little more than 90 minutes to beat Wimbledon debutant Adam Pavlasek 6-2 6-2 6-1.
On Court 17, Mattek-Sands was playing Romania's Sorana Cirstea when she appeared to slip as she approached the net at the beginning of the third set, then collapsed awkwardly on to the grass.
Medical personnel arrived and the 32-year-old was treated by doctors on the court for more than 20 minutes, during which time she was given oxygen and an injection.
In a mixed day for the title favourites, German top seed Angelique Kerber battled past Belgium's Kirsten Flipkens 7-5 7-5 in the second round but Czech third seed Karolina Pliskova was dumped out of the tournament.
Pliskova, who came into the championships on the back of a grasscourt title success in Eastbourne, was beaten 3-6 7-5 6-2 by 87th-ranked Slovak Magdalena Rybarikova.
WOZNIACKI MARCHES ON
Fifth seed Caroline Wozniacki of Denmark beat Bulgarian Tsvetana Pironkova 6-3 6-4 to book a place in the third round.
Germany's top seed Angelique Kerber sealed a 7-5 7-5 win over Belgian Kirsten Flipkens in the second round.
FEDERER CRUISES THROUGH TO ROUND THREE
Seven-time champion Roger Federer booked a third round place with a 7-6 (0) 6-3 6-2 win over Serbian Dusan Lajovic, ranked 79 in the world.
German Alexander Zverev beat American Frances Tiafoe 6-3 6-4 6-3 to join elder brother Mischa in the third round.
RAONIC SURVIVES YOUZHNY SCARE
Sixth seed Canadian Milos Raonic had to dig deep for his 3-6 7-6 (7) 6-4 7-5 victory over Russian Mikhail Youzhny in the second round.
KONTAVEIT DUMPS KASATKINA
Estonian Anett Kontaveit needed just 55 minutes to beat Russian 29th seed Daria Kasatkina 6-3 6-2 in the second round.
Czech Tomas Berdych recovered from a third-set tiebreak loss to beat American Ryan Harrison 6-4 6-3 6-7 (8) 6-3 in their second-round match on Court 12.
World No 15 Berdych, a 2010 finalist, progressed to the third round for the fifth consecutive time at the championships.
THIEM BOOKS ROUND THREE SPOT
Eighth seed Dominic Thiem beat Frenchman Gilles Simon 5-7 6-4 6-2 6-4 on Court One to reach the third round at Wimbledon for the first time.
RYBARIKOVA UPSETS PLISKOVA
Third seed Karolina Pliskova suffered a shock exit in the second round, losing 3-6 7-5 6-2 to world No 87 Magdalena Rybarikova.
CLINICAL MUGURUZA ADVANCES
Spaniard Garbine Muguruza committed just 10 unforced errors on her way to the third round with a 6-2 6-4 win over Yanina Wickmayer of Belgium.
It was the Muguruza's 25th match win of the calendar year.
American Bethanie Mattek-Sands suffered a serious knee injury and left the court in pain on a stretcher after stumbling at the beginning of the third set.
Mattek-Sands was treated by doctors on court for more than 20 minutes before being carried off.
She had won the first set 6-4 before losing the second set 7-6 (4) to Sorana Cirstea of Romania in the second round.
Mattek-Sands and her partner Lucie Safarova were bidding for a fourth straight doubles grand slam title at Wimbledon.
RISKE OUSTS MLADENOVIC
France's Kristina Mladenovic squandered her opening set lead to suffer a 2-6 6-4 6-4 to American Alison Riske on Court 18.
RADWANSKA PREVAILS IN THREE SETS
Ninth seed Agnieszka Radwanska saved two match points in the second set before defeating American Christina McHale 5-7 7-6 (7) 6-3 after two hours and 43 minutes on Court Two.
GULBIS STUNS DEL POTRO
World No 589 Ernests Gulbis knocked out 2013 semi-finalist Juan Martin del Potro 6-4 6-4 7-6 (3) on Court Three.
The 28-year-old Latvian, who like Del Potro has been struggling with injury in recent years, hit 60 winners and fired 25 aces to reach the third round for only the second time at the championships.
ISNER KNOCKED OUT
Big-serving American John Isner lost to Israel's Dudi Sela 6-7 (5) 7-6 (5) 5-7 7-6 (5) 6-3 after almost four hours of play on Court 12.
Since defeating Nicolas Mahut 70-68 in a record-breaking fifth set in 2010, Isner has lost all of his four 5-set encounters at the championships.
MONFILS BREAKS BRITISH HEARTS
Frenchman Gael Monfils beat home favourite Kyle Edmund 7-6 (1) 6-4 6-4 to reach the third round for the sixth time and equal his best performance at Wimbledon.
MISCHA OUTLASTS KUKUSHKIN
German 27th seed Mischa Zverev beat Kazakhstan's Mikhail Kukushkin 6-1 6-2 2-6 3-6 6-4 after an intense battle that lasted over three hours on Court 14.
Zverev moved to the third round for the first time at Wimbledon since 2008.
DJOKOVIC EASES INTO ROUND THREE
Three time champion Novak Djokovic beat Czech Adam Pavlasek 6-2 6-2 6-1 on Court One to reach the third round for the ninth year in a row.
Second seed Djokovic takes his win-loss record to 18-1 at the championships since 2014.
Bulgarian Grigor Dimitrov produced another fine performance to beat Cypriot Marcos Baghdatis 6-3 6-2 6-1 on Court Two.
Dimitrov, the 13th seed, progressed to the third round for the fourth consecutive year.
COCO CRUISES THROUGH
American Coco Vandeweghe beat German Tatjana Maria 6-4 6-2 to in their second-round match on Court 16.
Vandeweghe, who recently teamed-up with former men's champion Pat Cash, won 24 of 29 points at the net to reach the third round for the third consecutive year.
KUZNETSOVA ROMPS PAST MAKAROVA
Seventh seed Svetlana Kuznetsova needed just over an hour to book a spot in the third round, beating fellow Russian Ekaterina Makarova 6-0 7-5 on Court Three.
FERRER THROUGH AS DARCIS RETIRES
Spaniard David Ferrer reached the third round after his opponent Steve Darcis was forced to withdraw with a back problem.
Ferrer, twice a quarter-finalist, was leading 3-0 after 18 minutes of play on Court 17.