Sharapova struggled in a scream queen stand-off against No. 3 Victoria Azarenka, eventually prevailing 6-1, 2-6, 6-3, while Serena muscled past No. 5 Sara Errani 6-0, 6-1.

Djokovic put down a challenge from No. 12 seed and near-AARP member Tommy Haas 6-3, 7-6(5), 7-5, while Nadal ran through the hot-handed No. 9 seed Stan Wawrinka 6-2, 6-3, 6-1 in matches inexplicably scheduled at the same time at Roland Garros.

Federer, who next meets the No. 15 seed Simon who has been tested in long matches, was also on the energy-conserving tip.

“That’s one of the best wins of my career,” said Mattek-Sands, who hit 32 winners during the aggressive assault. “I knew she wasn’t going to give it to me. She’s a champion, and I had to play some of my best tennis ever to beat her…It was kind of a battle of who can take control of that middle court.”

“It’s always tough to say, but I definitely feel like clay is probably not my favorite surface,” said Wozniacki, who added she will now start her Wimbledon preparation. “It hasn’t been the best clay season for me. Obviously I would have liked to play longer and play better, but it wasn’t to be.”

Rafael Nadal looked sharp in his Madrid opener today at the Magic Box.

“There were a lot of ups and downs — when you don’t play so much, you kind of lose how to feel that momentum in the match,” Azarenka said. “I was just playing a little bit stupid, I think, and she definitely got loose and nothing to lose.”

Notes: Insane field with two former No. 1s and an additional Slam champ all unseeded…The Top 3 seeds are current or former No. 1s…Tough opening-round matches are (5) Na vs. Tamira Paszek then the winner of Venus and (WC) Medina Garrigues, (3) Azarenka vs. Pavlyuchenkova, (11) Petrova vs. a qualifier then likely Kuznetsova, (16) Ivanovic vs. a qualifier then likely her Serb countrywoman Jankovic, (9) Stosur vs. the clay-savvy Suarez Navarro, and (2) Sharapova vs. a qualifier then likely Peng…No blue clay this year…Former champs in the field are Serena Williams (2012) and Kvitova (2011).

Notes: Interesting start for (2) Bartoli vs. the free-swinging American Vandeweghe…wildcards went to (4) Ivanovic and Mexicans Ximena Hermoso and Ana Sof�a Sanchez…notable pulls from the draw were Victoria Azarenka (right ankle, missed a chunk of cash), Kirsten Flipkens, Aleksandra Wozniak (shoulder), and Vera Zvonareva (shoulder)…Returning former champs in the field are Pavlyuchenkova (2011-10) and Bartoli (2009).

On a night when the grounds went dark, Novak Djokovic suffered no power outage in Miami, crushing Lukos Rosol. But Juan Martin Del Potro wasn’t as fortunate in an opening round bracket busting loss.