LONDON -- Maria Sharapova reached up and flicked an over-the-shoulder backhand volley for a winner to wrap up a close-as-can-be first set.
About an hour later, she just as easily swatted away questions from reporters hungry for more juice in her feud with Serena Williams.
"I've said everything that I wanted to say about the issue," the third-seeded Russian said Monday after a 7-6 (5), 6-3 victory over Kristina Mladenovic of France. "Wimbledon started. This is my work. This is my job. I'd really appreciate it if we move on."
It was time for tennis after a week of buildup that included the news-making back-and-forth between Sharapova and Williams, stemming from comments Williams made in a Rolling Stone magazine interview.
Opening her stay at the All England Club on Centre Court, the 2004 champion got off to a slow start.
The tiebreaker was jittery, but with the score tied at 5, Sharapova came up with a backhand crosscourt winner, followed by the backhand overhead volley to close out the set. Sharapova broke in the fourth game of the second set and served it out from there.
It was a tricky test for the first round of a Grand Slam, against 37th-ranked Mladenovic, who came in with a 73-15 career record on grass.
"I'm really happy with the way I came out and played my first match," Sharapova said. " The first ones are always pretty tough, especially on the grass."
Williams, who beat Sharapova in the French Open final earlier this month, opens defense of her title Tuesday against Mandy Minella.
Azarenka won the first set easily and was ahead 1-0 in the second when she slipped and fell. She was sobbing on the court and received treatment during an injury timeout. She played the rest of the match with a heavy wrap on her right knee.
After resuming, Azarenka was limping noticeably and winced after several points. But Koehler, making her Wimbledon debut, did not have the power or consistency to make Azarenka, the two-time Australian Open titlist, pay for her diminished mobility.
"I was in such pain at the beginning, it wouldn't let go," Azarenka said. "I think it calmed down."
Wimbledon also produced its first upset on the opening day of the tournament.
The 19-year-old Puig, playing her first grass-court tournament as a pro, completely outplayed the Italian veteran with her hard-hitting baseline game.
Puig said she has been building on a recent run of success, including a third-round showing at the French Open.
"Definitely pulling off some big career wins and not being afraid to close out matches, which was my problem at the beginning of the year," she said. "Finally just having the confidence to close them out."
Errani was runner-up at last year's French Open and had reached at least the semifinals of three of the past five Grand Slams. But on the slick grass at the All England club Monday, she had only 13 winners and was broken four times.
Puig squandered five match points before hitting a forehand winner past Errani to close out the match. The Puerto Rican dropped her racket to the turf and covered her face in her hands.
Errani withdrew from last week's grass-court warm-up at Eastbourne with a leg injury but showed no signs of any physical problems during the match.
It's the third time a top-five-seeded women's player has lost in the first round at Wimbledon since 2001. The others were Martina Hingis in 2000 and Francesca Schiavone in 2010.
Monday's defeat marked another humbling Wimbledon exit for Errani.
Last year, the Italian went an entire set without winning a point in losing 6-0, 6-4 in the third round to Yaroslava Shvedova of Kazakhstan. Shvedova was the first player in a Grand Slam to achieve a so-called "golden set" by winning 24 straight points.
The 12th-seeded Ivanovic, a semifinalist here in 2007, swept through the second set in 22 minutes, finishing the match with her sixth ace.
The weather was cloudy but dry for the beginning of the two-week championships.
Information from The Associated Press was used in this report.