Australian Lleyton Hewitt scored a big upset at the scene of one of his greatest triumphs, rallying to stun Argentine Juan Martin del Potro 6-4, 5-7, 3-6, 7-6 (7-2), 6-1 in a battle of former champions at the U.S. Open.

The 32-year-old Hewitt, who defeated American great Pete Sampras on Arthur Ashe Stadium in the 2001 final, employed a strategy Friday night based on changing up the pace and placement of his shots and not letting the No. 6 seed dictate the points with his powerful forehand.

The tactics worked early as the gritty Australian, now in the sunset of his career and ranked No. 66, won the first set and served for a two-set lead at 5-4 in the second set of the second-round match.

Hewitt, however, committed a pair of costly double faults in that game that shifted the momentum in the favor of 2009 champion, who reeled off nine out of 12 games to take a two-set-to-one lead.

The fourth set then proved to be a roller coaster, as Hewitt squandered a chance to serve it out in the ninth game but proceeded to hang tough and dominate the tiebreaker to force a decider.

The fifth set came down to stamina and the 24-year-old Del Potro, who appeared to be suffering the effects of a grueling first-round battle with Spain's Guillermo Garcia-Lopez, was no long able to hold up his own in the baseline rallies.

"It was unbelievable atmosphere. I just kept fighting and putting it out there, you know, I kept coming at him the whole night. Felt like I was seeing the ball well. Felt like I played a good game plan for most of the night as well," Hewitt said in the post-match interview.

Asked about the chance to play once again on stadium court, Hewitt, who has struggled with a serious foot injury in recent years, said he was "happy" because "I don't know how many times I'm going to play here in the future ... I didn't take it for granted out there tonight."

Next up for the Australian will be Russian Evgeny Donskoy, who advanced to the third round with a 6-3, 6-4, 3-6, 4-6, 6-3 win over Germany's Peter Gojowczyk. EFE