* Eighth seed powers past Levine in straight sets
* Remains on course for Djokovic semi-final (Adds details, quotes)
LONDON, June 27 (Reuters) - Giant Argentine Juan Martin Del Potro moved sure-footedly into the third round of Wimbledon with a ruthlessly impressive straight-sets Centre Court win over American-turned Canadian Jesse Levine on Thursday.
The 6ft 6ins (1.98m) eighth seed, seeking a second grand slam title after his 2009 U.S. Open success, won 6-2 7-6(7) 6-3 with a display of crushing power but also showed an athletic balance on the lush grass that caused so many problems on Wednesday.
Left-handed outsider Levine was edgy and blown away in the opening set, rallied briefly in an entertaining slug-fest of a second but had no answers in the third as he was overwhelmed by Del Potro's growing weight of shot.
"He's a good fighter and a lefty on grass is tough," said Del Potro. "In the second set I got lucky but by the end I was playing well and my serve was good."
Del Potro, who missed last month's French Open through illness, has spent most of his career shadowing the "big four" and although two of them - Novak Djokovic and Andy Murray - could still stand in his way at Wimbledon next week he showed again that he has all the tools to break the cartel.
His 2009 U.S. Open final victory over Roger Federer appeared to mark the then-20-year-old as the coming force in the game but a serious wrist injury virtually wrote off the following season and he has been struggling to reach the same heights since, failing to get past the quarter-finals of any grand slam.
He is showing glimpses of that peak form again this week, however, as he followed up his quick-fire dismissal of Spain's Albert Ramos with another clean-striking sub-two-hour win.
The 25-year-old Levine, on his Centre Court debut, was a bag of nerves initially and dropped his opening two service games, the second after two ragged double-faults.
He settled into his game in the second set, going toe-to-toe with Del Potro as both men drew gasps from the crowd with a series of crushing, geometry-defying forehands.
Ottawa-born Levine, playing Wimbledon as a Canadian for the first time after switching nationality seven months ago, served for the set but two loose shots saw the advantage slip away and Del Potro went on to take the all-important tiebreak.
That setback seemed to break Levine's spirit and, with Del Potro's 130mph service on song, there was only going to be one winner.
"I've got good memories from last year at the Olympics and I enjoy playing on grass," he said looking back to his bronze medal victory over Djokovic that should stand him in good stead mentally should he face the top seed in the semi-finals.
He is not likely to be cowed by the Serb's legendary fitness, either, having showcased his own stamina in that remarkable 19-17, 2 hour 43 minute third set in his Olympic semi-final defeat by Roger Federer. (Editing by Ken Ferris)