Former US Open champion Juan Martin del Potro claimed his first victory in a nearly a year as he progressed to the second round at the Sydney International.

19155 - Del Potro returns to winning ways in Sydney

Del Potro, who was seeded fourth for the Australian Open last year but has since fallen outside the world's top 250 after suffering a wrist injury last January, underwent a gruelling fitness test as he was forced to save match point to beat Feliciano Lopez 6-7(5) 7-6(9) 7-6(3) after three hours and 20 minutes on Monday.

Del Potro lost to Lopez in his last ATP Tour match in October, and he grabbed an early break but was pegged back by the sixth seed who clinched the opener on a tiebreak. Lopez had his chance to seal victory in the second at 7-6 in the tiebreak, but del Potro hung on to take the match to a decider. The former world No4 4 was forced to save six break points in the final set, but managed to cling on for a hard-fought victory.

"I don't expect this kind of match for the start, but we played a beautiful match, very close," said del Potro. "Feliciano is a fantastic player on this kind of surface, and I played good tennis again. I feel good all on my match, and finally I won a match since one year."

The victory sees del Potro progress to the second round, where he will meet Florian Mayer, who ended British wildcard James Ward's hopes. Ward battled valiantly but was beaten 7-5 6-0 by the German. Mayer and del Potro's last meeting came at the 2010 Australian Open - the Argentine's last competitive victory.

Russian qualifier Igor Andreev progressed to the second round with a 6-2 6-4 win over Jeremy Chardy, while Benjamin Becker was ousted by Sergiy Stakhovsky 7-6(3) 7-6(6).

Jarkko Nieminen was forced to withdraw from his match against Portuguese qualifier Frederico Gil with a knee injury, while Lukasz Kubot was elevated into the main draw following Marcos Baghdatis' withdrawal with a groin problem.

Meanwhile, at the Heineken Open in Auckland, eighth seed Philipp Kohlschreiber was made to work hard for his victory over Carlos Berlocq. Kohlschreiber overcame a sluggish start to progress to the second round with a 2-6 6-3 6-1 win to set up a second round clash against either Bobby Reynolds or Marcel Granollers.

Tommy Robredo also had to battle back from a set down to beat local favourite Michael Venus. The world No. 330 gave a good account of himself as he won the opening set on a tiebreak, but Robredo showed his class to seal a 6-7(6) 6-3 6-0 victory. Also through to the second round is Santiago Giraldo, who beat Daniel Gimeno-Traver 6-2 6-4.