Victoria Azarenka and her fellow former world No. 1 Maria Sharapova reached the second round, while former French Open runner-up Sara Errani was a stunning opening-round loser Monday on opening day at The Championships, Wimbledon.
The second-seeded Azarenka whipped Portugal's Maria Joao Koehler 6-1, 6-2 on Court 1, while the third-seeded Sharapova got past capable Frenchwoman Kristina Mladenovic 7-6 (7-5), 6-3 on the grass on the famed Centre Court at the storied All England Club. Azarenka has now won 19 of her last 21 Grand Slam matches.
The career Grand Slam winner Sharapova captured her lone Wimbledon title in 2004 and was the 2011 runner-up at the prestigious event. The Russian star was this month's French Open runner-up to Serena Williams and also lost to Williams in last year's Olympic gold-medal match here at the All England Club.
Up next for Sharapova will be Portuguese Michelle Larcher de Brito.
The Australian Open champion and U.S. Open runner-up Azarenka suffered a knee injury while up a set and leading 1-0 in the second against Koehler.
The Belarusian star, who is no stranger to injury drama, wound up doing a split behind the baseline at one point, injuring her right knee, which required treatment on three separate occasions. Azarenka was laying on the court crying and screaming when the injury occurred.
"I don't know what happened out there," Azarenka said. "I was just trying to stay in the moment and give the best I can. But it was definitely very emotional. I couldn't believe what happened. I was in such shock.
"I was in such pain at the beginning, it wouldn't let go. I think it calmed down."
The two-time Wimbledon semifinalist Azarenka hobbled around the court a bit after the injury, but ultimately had no problem advancing on Day 1.
Her second-round opponent will be former top-10 player Flavia Pennetta of Italy.
Earlier Monday, it didn't take long for the first upset to occur, as Puerto Rico's Monica Puig ousted the fifth-seeded Errani at the year's third Grand Slam event.
Puig claimed a 6-3, 6-2 victory over Errani, who has not had much success on the Wimbledon grass. The Italian was making her sixth visit and has never been past the third round. Clay is clearly her favorite surface, evidenced by a surprise run to the final at last year's French Open and a semifinal appearance at Roland Garros earlier this month.
This is the first Wimbledon appearance for the 19-year-old Puig, who reached the third round at the French Open.
Eighth-seeded former Wimbledon champ Petra Kvitova outlasted game American Coco Vandeweghe 6-1, 5-7, 6-4, while ninth-seeded former world No. 1 Caroline Wozniacki looked sharp in beating Spaniard Estrella Cabeza Candela 6-0, 6-2. The left-handed Czech Kvitova topped Sharapova in the 2011 Wimbledon finale. The former U.S. Open runner-up Wozniacki has never reached the quarterfinals at Wimbledon.
Kvitova's second-round opponent will be Kazakhstan's Yaroslava Shvedova, while Wozniacki will take on Czech Petra Cetkovska.
Serbia's Ana Ivanovic battled through a tough first set against Frenchwoman Virginie Razzano, then rolled in the second to complete a 7-6 (7-1), 6-0 triumph, while another Serbian former world No. 1, 16th-seeded Jelena Jankovic, handled Aussie Johanna Konta 6-2, 7-5. The former French Open champion Ivanovic, seeded 12th this year, has advanced past the fourth round just once in eight previous Wimbledon visits -- a semifinal run in 2007. The former U.S. Open runner-up Jankovic has never reached the quarterfinals at Wimbledon.
American Sloane Stephens, seeded 17th here, dismissed compatriot Jamie Hampton 6-3, 6-3. The 23-year-old Hampton was a grass-court runner-up in Eastbourne last week.
The Aussie Open semifinalist Stephens will meet former top-10 German Andrea Petkovic on Wednesday.
Meanwhile, 15th-seeded former Wimbledon runner-up Marion Bartoli of France defeated Ukrainian Elina Svitolina 6-3, 7-5; 19th-seeded Carla Suarez Navarro drubbed fellow Spaniard Lourdes Dominguez Lino 6-2, 6-2; 20th-seeded Belgian Kirsten Flipkens downed Russian Yulia Putintseva 7-5, 6-4; 22nd-seeded Romanian Sorana Cirstea subdued Swiss Stefanie Voegele 7-5, 7-6 (7-3); 25th- seeded Russian Ekaterina Makarova eased past Swede Johanna Larsson, 6-3, 6-3; Czech Eva Birnerova upended 26th-seeded American Varvara Lepchenko 6-2, 4-6, 6-4; 27th-seeded Czech Lucie Safarova leveled American Lauren Davis 6-4, 6-0; and 29th-seeded Frenchwoman Alize Cornet overcame American Vania King 4-6, 6-3, 6-1. Flipkens was a grass-court runner-up in The Netherlands last week.
Several other women advanced on Monday, including the aforementioned Pennetta, Petkovic, American Christina McHale, and Canadian Eugenie Bouchard.
On Tuesday, a top-seeded Williams will open her stay here against Luxembourg's Mandy Minella.
Williams is the reigning Wimbledon, French Open and U.S. Open champion who owns 16 Grand Slam singles titles overall, including five Wimbledon victories.
Also slated for Day-2 action are fourth-seeded 2012 Wimbledon runner-up Agnieszka Radwanska and sixth-seeded Aussie Open runner-up and former French Open champ Li Na.