Miami  - Roger Federer polished his mighty game at the continued expense of Nicolas Kiefer as he hammered the German 6-4, 6-1 to rip into a third-round place on a cloudy, muggy Sunday afternoon at the Miami Masters.

The Swiss second seed and two-time winner at Crandon Park spent little more than an hour in the rout and never faced a break point as he beat the veteran for the 11th consecutive time.

"Kiwi is the only player whom I've beaten at all four Grand Slams," said Federer, searching for his first title of 2009. "It was very windy out there today and I know he doesn't like those conditions.

"I tried to really place my first serve, knowing that I can always count on my second. I'm happy to get a good win and move ahead," said the 13-time Grand Slam winner who has faced Kiefer every year starting in 2000.

Federer will next play Taylor Dent, coming back from several years of back problems including operations and time in a body cast. The American booked his fourth-round spot over Spanish 15th seed Tommy Robredo 7-5, 6-3.

Fifth seed Andy Roddick complained to no avail about a slippery court as he defeated Dmitry Tursunov 7-6 (11-9), 6-2. Roddick expressed his opinions forcibly to chair umpire Norm Chryst without satisfaction as tempers flared briefly on centre court.

"I basically was wondering how many more times we were going to play on a slippery court," said Roddick. "He said, 'Well, no one has fallen yet.' I said, 'Well, if that's a barometer, then we have a problem.'"

The 2004 Miami champion fired 11 aces in his winning effort.

French seventh seed Gilles Simon staged a fightback to beat ATP comeback player of the year Rainer Schuettler, putting out the German 3-6, 6-1, 6-1.

Compatriot Gael Monfils outlasted Marat Safin 5-7, 7-5, 7-6 (7-3) in a third-set comeback thriller while France's Jo-Wilfried Tsonga stopped Robert Kendrick 7-5, 6-4.

Women's seed suffered a run of upsets, with number 2 Dinara Safina ushered out 6-1, 6-4 by on-form Australian Samantha Stosur.

Safina, who lost a chance to take over the No 1 WTA ranking from Serena Williams last week in Indian Wells, gave up any chance of advancing in Miami as she went down to Stosur, ranked 42nd.

"It was just a disaster match," said the disillusioned Russian. "I just started to play a little bit better at 6-1, 3-love, but it was too late.

"She's a great player, she played very good. But I just can say it was sad the way I played today. Basically I wasn't playing."

The upsets didn't stop with the Russian, as Serb Ana Ivanovic followed compatriot Jelena Jankovic out the door in a loss to Hungarian Agnes Szavay 6-4, 4-6, 6-1.

Serbian hopes - which burned so brightly in 2008 when Ivanovic won the French Open, Jankovic ended the season number 1 and Djokovic claimed the Australian Open title - have dimmed considerably.

"I hardly did anything well today, I was really disappointed," said Ivanovic.

China's Li Na sent out sixth seed Vera Zvonareva 6-4, 3-6, 6-2. Top seed Serena Williams beat Peng Shuai 7-5, 6-2.

Olympic champion Elena Dementieva steadied for seeds, with the No 4 beating Spain's Carla Suarez Navarro 6-2, 6-2.

The Russian was joined in the fourth round by number 5 Venus Williams, who beat Germany's Anna-Lena Groenefeld 7-5, 6-3, Russian Svetlana Kuznetsova, a winner over Nicole Vaidisova 6-1, 6-4 and number 11 Victoria Azarenka, who stopped Anna Chakvetadze 6-1, 6-4. (dpa)