Querrey, Isner Lead Four Americans Through

© Getty ImagesSam Querrey improved to a 12-7 match record on the season.

ATP World No. 47 Sam Querrey led four Americans through to the second round of the Sony Ericsson Open on Thursday. Querrey knocked out Gilles Muller of Luxembourg 6-4, 6-3 at the ATP World Tour Masters 1000 tennis tournament in Miami.

The 21-year-old Querrey fired nine aces and converted three of five break point chances to dismiss Muller in front of the Stadium crowd in just 66 minutes. The California native is through to the Sony Ericsson Open second round for a third straight year and next will face Feliciano Lopez, the No. 32 seed from Spain.

Querrey improved to a 12-7 match record on the season. The right-hander reached his second ATP World Tour final in the second week of the season at Auckland (l. to del Potro) and advanced to back-to-back quarter-finals in San Jose (l. to Blake) and Memphis (l. to Roddick).

American qualifier John Isner continued his recent good form by defeating Ukrainian Sergiy Stakhovsky 6-4, 6-4.

The 23-year-old Isner was dominant on serve in his first meeting with World No. 119 Stakhovsky, firing 12 aces and surrendering just seven points behind his first serve in the 74-minute match. The right-hander is through to the Sony Ericsson Open second round for the first time and will face Spanish No. 11 seed David Ferrer.

World No. 134 Isner is coming off a career-best fourth round result in an ATP World Tour Masters 1000 tennis tournament in Indian Wells last week (d. No. 9 Monfils,. l. to No. 6 del Potro). The towering Tampa resident (6’9’’), who did not drop serve in Thursday’s match (saved one break point), ranked No. 4 in service games won (89%) and No. 7 in aces (156) in the Ricoh ATP Matchfacts coming into the week.

“I'm pretty confident right now. I do have some momentum on my side, so that's helped me here,” said Isner. Looking ahead to his clash with Ferrer he said: “The guy is tough. He makes a lot of balls, and he's in unbelievable shape. He's like a bulldog out there, real feisty and doesn't give anything up. I'm going to have to beat him, that's for sure. He's not going to beat himself. Hopefully I can go in there with a good game plan. Like I said, I am confident. I'm going to need to serve well and return well and hit some big groundstrokes and kind of throw off his rhythm a little bit.”

A second American qualifier also advanced as Amer Delic fired 17 aces to edge past Belgian Steve Darcis 6-4, 7-6(2) in 83 minutes. It was the third tour-level main draw victory (3-2 record) of the season for World No. 130 Delic, who reached the third round at the Australian Open (l. to Djokovic) in January. He next will meet Marin Cilic, the No. 17 seed from Croatia and two-time ATP World Tour titlist this season, as he looks for a repeat of his 2007 Sony Ericsson Open success – when he defeated World No. 4 Nikolay Davydenko to reach the fourth round.

With Frederico Gil’s 7-6(7), 6-2 victory over Mischa Zverev and Benjamin Becker’s 6-4, 6-3 win against Jesse Levine, qualifiers went 4-0 in Thursday’s action – lifting the first round record to a sparkling 10-2, which ties the tournament record set in 1990.

American Bobby Reynolds suffered a bagel first set to fight back and defeat Juan Ignacio Chela 0-6, 7-5, 6-4 and set up a second round meeting with Czech No. 18 seed Radek Stepanek.

Russian Teimuraz Gabashvili earned a second round clash with World No. 1 Rafael Nadal after battling past Italy’s Simone Bolelli 6-4, 4-6, 6-4. The 72nd-ranked Gabashvili also reached the Sony Ericsson Open second round in 2007 (l. to Youzhny).