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.

Qualifier Ryan Sweeting missed out on his first ATP quarter-final as sixth-seeded American compatriot Sam Querrey recovered after a disaster second set to sweep their contest 6-3, 6-7 (5-7), 6-3.

Querrey won the first set, recovered from 0-5 down in the second to take it into a tiebreaker but failed to close it out. It finally went the distance before the seed advanced.

'I wanted to forget about the second set and start the third clean,' said Querrey. 'I went into the third with a fresh mind.'

Querrey, 21, has now reached 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.