KEY BISCAYNE, Fla. -- Trailing in the first set of her first match at the Sony Open, Serena Williams grunted with every shot and screamed with every point she won.
And then, on the pivotal point, she didn't make a sound -- or take a swing.
Williams capitalized on a critical double-fault Thursday by Yaroslava Shvedova to survive a 69-minute first set and win, 7-6 (7), 6-2.
"It was an incredibly tough first set," Williams said. "I just needed to relax and yet keep up the intensity."
The top-ranked Williams seeks a record seventh Key Biscayne title, and her second in a row.
Williams, who owns a small share of the Miami Dolphins, wore a dress in the team's orange and turquoise colors -- which may explain her slow start. Or maybe it was because she hadn't played since Feb. 21.
Williams had to erase a 5-3 deficit in the first set, and then fell behind 6-3 in the tiebreaker. Shvedova pushed a forehand into the net, then hit a nervous double-fault that allowed Williams to exhale.
She won the next two points with aces, then closed out the set with a backhand winner, a fist pump and a scream of "Yes!"
Her game steadied in the second set, when she had 18 winners and only 10 unforced errors -- bad news perhaps for opponents to come in the tournament Williams considers her hometown event. She lives an hour up I-95 in Palm Beach Gardens.
"I obviously love playing here," she told the crowd. "I'm just happy to have a win today."
Friday's stadium court schedule features the winners of 34 Grand Slam titles in five matches. The parade of champions will include Federer, Novak Djokovic, Venus Williams, Andy Murray and Li Na playing their opening matches.