Lleyton Hewitt has rolled back the years to defeat Juan Martin del Potro in an exhilarating four-hour battle at Flushing Meadows.

The Australian, who won the US Open title in 2001, was 2-1 down in sets but came up with the goods with his back against the wall on Arthur Ashe.

The 32-year-old needed just the one break point to snatch a tight first set 6-4, but the 2010 champion responded by taking the next set 7-5.

The sixth seed converted two of his three break points to edge ahead after the third set, but Hewitt roared back in the fourth, breaking at 5-3 for the chance to serve out.

However, the Australian stumbled as he approached the finishing line, allowing Del Potro what turned out to be a temporary reprieve as he dominated the fourth-set tie-breaker 7-2.

It was Hewitt who finished strongly in the deciding set, storming to a 6-1 victory for the prize of a third-round match with Russia's Evgeny Donskoy Russia, who beat Peter Gojowczyk 6-3 6-4 3-6 4-6 6-3.