KEY BISCAYNE, Fla. -- Sam Querrey has won for the first time as the top-ranked American, rallying past Lukasz Kubot 4-6, 6-3, 6-3 at the Sony Open.

Querrey is ranked 20th and this week moved ahead of fellow American John Isner, who is 23rd.

On a sunny, humid afternoon Saturday, No. 6-seeded Jo-Wilfried Tsonga beat Viktor Troicki 7-6 (6), 6-3. No. 8 Richard Gasquet defeated qualifier Olivier Rochus 7-5, 6-2.

No. 18 Philipp Kohlschreiber lost to David Goffin 7-6 (5), 4-6, 6-2. In women's play, No. 5 Li Na beat No. 25 Varvara Lepchenko of the United States 6-2, 6-4.

Querrey lost his first serve game but held the rest of the way and hit 12 aces against Kubot.