Novak Djokovic declared himself in career-best form after trouncing veteran James Blake 6-2, 6-0 on Sunday in the third round of the Sony Ericsson Open in Key Biscayne, Florida.

The No. 2-seeded Serb extended his winning streak to 22 consecutive matches. He has lost just three games in two matches at this tournament and his 20-0 start to 2011 is the best record to begin a year since Ivan Lendl started 25-0 in 1986.

"It has been a dream run for me the last couple of months," Djokovic said. "I'm playing the best tennis of my life."

Another man eyeing a career high is Mardy Fish, who moved within two wins of becoming America's top-ranked men's player after beating Richard Gasquet 6-4, 6-3.

Fish is ranked a career-best 15th and is poised to overtake longtime friend Andy Roddick in the next rankings. Roddick lost his opening match on Saturday and is expected to drop from eighth to about 15th, the lowest he has been ranked since 2002.

"I certainly wouldn't feel like the top-ranked American, considering what Andy has accomplished and what I've accomplished," Fish said. "His career has quadrupled mine, at least."

Roddick is a five-time grand slam finalist who won the 2003 US Open and finished that year ranked No. 1. Fish's record in major events is mediocre and he has made the top 20 in the year-end rankings only twice.

But at 29, Fish is in the best condition of his career. That showed against Gasquet in the hot midday sun.

Fish's next opponent will be Juan Martin del Potro, who is gaining momentum in his comeback from wrist surgery last May. The big Argentine earned his first win this year over a top-10 player by beating No. 4 Robin Soderling 6-3, 6-2.

Del Potro, ranked 484th in February, will climb back into the top 45 after the tournament.

Sixth-seeded David Ferrer of Spain also progressed, defeating India's Somdev Devvarman 6-4, 6-2.

In women's play, No. 2-seeded Kim Clijsters earned her 500th career victory by beating Maria Jose Martinez Sanchez, 6-4, 4-6, 6-3.

Clijsters, who won the tournament in 2005 and 2010, advanced to the fourth round despite 10 double-faults and 39 unforced errors.

She next plays No. 19 Ana Ivanovic, who won when Virginie Razzano retired trailing 2-6, 6-2, 3-0.

Reigning French Open champion Francesca Schiavone, seeded fifth, edged Lourdes Dominguez Lino 6-4, 7-6 (2). No. 9 Agnieszka Radwanska beat No. 24 Maria Kirilenko 7-6 (2), 6-3.