Los Angeles  - Israeli Dudi Sela continued his charge from a standing start this season, with the number 30 posting a 6-4, 3-6, 6- 1 victory over American Robert Kendrick to reach the quarter-finals of the Los Angeles Open Thursday.

Fourth seed Sela, who began the year at around 100, moved into his third quarter-final of the season after getting to the stage just once each during the 2007 and 2008 campaigns.

"I worked hard on my fitness and my game in the off-season," said the 24-year-old, who also played the Memphis semi-finals early in the year. "It was nothing special, just taking things more seriously and improving my game."

Sela played on the record-setting Israeli Davis Cup team, which has put the nation into a first semi-final in the worldwide event. Argentine outsider Leonardo Mayer sprang an upset on fifth seed Igor Kunitsyn, dispatching the Russian 7-6 (7-5), 6-7 (7-9), 6-3 in a shade under three hours.

Kunitsyn's 2009 record now stands at nine wins and 20 losses, with the number 37 outplayed by his 60th-ranked opponent.

Mayer fired nine aces and broke five times to line up against the winner from second seed Mardy Fish and revitalized Australian wild card Chris Guccione.

Qualifier Ryan Sweeting was aiming for his first ATP quarter-final against sixth seeded American compatriot Sam Querrey in the pair's first match-up.

Querrey, 21, is hoping to reach a third consecutive last-eight place after Newport and Indianapolis last week. The career-best 32nd also lost finals in those last two events and stands 28-18 on the season. (dpa0