Stanislas Wawrinka has safely dispatched Ivo Karlovic in straight sets to advance to the third round of the US Open.

The Swiss number two edged the first set 7-5, but he was taken all the way in a marathon second set, which lasted 66 minutes.

The tie-breaker was every bit as close, but it was Wawrinka who prevailed 10-8.

Karlovic met the 28-year-old in clinical form as he needed just the one break point to seal the third set 6-4.

His reward is a third-round showdown with Marcos Baghdatis, who destroyed Kevin Anderson 6-2 6-2 6-2.