MIAMI, FL, USA - Venus Williams extended her winning streak to 11 matches on Thursday night at the Sony Ericsson Open, defeating Sorana Cirstea in straight sets in her first match of the $4.5-million tournament, 64 63.

Watch live matches from Miami this fortnight on TennisTV.com!

Williams, seeded No.3, was down a break to the Romanian in both sets but fought back each time, eventually winning their first duel in 78 minutes. She fired six aces during the night-time encounter. Although she isn't the top seed, Williams is largely considered the best pick for the Miami title this year. She has won it three times before - two more than anyone else in the draw - and has the fifth-best winning percentage of all time here too (84%).

"I hadn't played in a few weeks, so it took some time to get some rhythm going," Williams said. "She played extremely aggressively - when her shots were going in, it was good stuff. Toward the end my game got better and better."

Have a look at some of Venus' best career moments right here!

The true top seed, Svetlana Kuznetsova, had a much more difficult time in her first match of the tournament, edging Peng Shuai in just under two hours, 62 36 64. Kuznetsova was two points away from losing serve at 4-all third set but held, then broke the Chinese at 15 to seal the deal in her opening match.

"I stopped moving my feet in the second set and lost a game, and then it all started to go wrong," Kuznetsova said. "I started talking to myself a bit better and stopped being so negative, and then cut down on my errors. Now I'm just going to try to get through my next round and go from there."

There were mixed results for the other Top 10 seeds in action. No.6 seed Agnieszka Radwanska advanced but the other two weren't so lucky, No.8 seed Li Na falling to Timea Bacsinszky, 64 46 76(3), and No.10 seed Flavia Pennetta falling to Andrea Petkovic after a 23-minute third set, 63 36 60.

No.12 seed Yanina Wickmayer, No.13 seed Marion Bartoli, No.16 seed Nadia Petrova and No.19 seed Daniela Hantuchova were also winners.

The player awards took place on Wednesday - check out the pics!

Earlier on, former world No.1 Ana Ivanovic - the No.25 seed here - got back on the winning track, beating qualifier Pauline Parmentier, 64 63.

"It was good to have a win," said Ivanovic, who came into this tournament on a four-match losing streak - and an eight-set losing streak. "I feel I am improving again. Obviously working with a new coach, Heinz Gunthardt, I can see the improvements on a daily basis. It's very encouraging for me going forward.

"I feel I've been playing better for a while now, so it was disappointing to lose so early at Indian Wells. But I'm just working hard and trying to do my best out there. I played well today. I stuck with what I've been working on."