Sweeting Sinks Sam

HOUSTON - Half of the quarterfinal positions in the US Men's Clay Court Championship were filled during play on Wednesday, but missing from the final eight will be second seed Sam Querrey who was upset by wild card Ryan Sweeting.

There were 11 breaks of serve in the match as Sweeting downed Querrey 3-6 7-6(5) 6-3. This marks the second time in 2011 that Sweeting has defeated Querrey to reach a quarterfinal, having done so at Delray Beach in February as well.

This is the second career quarterfinal for Sweeting, who will play Teymuraz Gabashvili in Friday's quarterfinal after the Russian took out No. 8 seed Grigor Dimitrov 7-6(4) 6-3 on Wednesday.

Another American will join Sweeting in the quarterfinals, as No. 4 seed John Isner recorded a 7-5 6-3 win over Argentine Horacio Zeballos.

The 6-foot-9 Isner will now face 6-foot-10 Ivo Karlovic, the 2007 tournament champion, who continued his run with a 6-4 6-1 win over Igor Kunitsyn.

The run by Karlovic is the deepest by a qualifier in this tournament since 2007 when Mariano Zabaleta qualified and reached the final where he lost, ironically, to Karlovic.

In doubles the top two seeds, Bob & Mike Bryan and Eric Butorac & Jean-Julien Rojer, were the first teams to advance to the semifinals.

The Bryans picked up their 14th straight win in Houston by downing Santiago Gonzalez & Ricardo Mello 6-3 6-4. Butorac & Rojer advanced with a 7-6(5) 6-4 win over Carlos Berlocq & Gabashvili.

Here's a look at Wednesday's results and Thursday's schedule:

RESULTS - WEDNESDAY, APRIL 6, 2011
Singles Second Round
[WC] Ryan Sweeting (USA) d [2] Sam Querrey (USA) 36 76(5) 63
[4] John Isner (USA) d Horacio Zeballos (ARG) 75 63
Teymuraz Gabashvili (RUS) d [8] Grigor Dimitrov (BUL) 76(4) 63
[Q] Ivo Karlovic (CRO) d Igor Kunitsyn (RUS) 64 61

Singles Second Round
[1] Bob Bryan (USA) / Mike Bryan (USA) d Santiago Gonzalez (MEX) / Ricardo Mello (BRA) 63 64
[2] Eric Butorac (USA) / Jean-Julien Rojer (AHO) d Carlos Berlocq (ARG) / Teymuraz Gabashvili (RUS) 76(5) 64