Tommy Robredo came back from two sets down to knock Simone Bolelli out of the US Open and reach the third round of the Grand Slam.

The Spanish 16th seed was the clear favourite to progress, but it looked like there might be a shock on the cards when the Italian edged a close first set 7-5.

Robredo looked in trouble as the second set went to a tie-break, which Bolelli won 7-5, but he soon began to stage a fightback.

However, there was controversy in the third set as the Spaniard broke at the fourth time of asking with the help of somebody in the crowd.

Bolelli stopped mid-point after hearing the call of "out", but it appeared to come from the audience rather than the umpire, with the official ruling that the Italian must concede the point.

After taking the third 6-4, Robredo, broke into his stride and levelled the match at two sets each when he claimed the fourth 6-3.

He rounded off the match by claiming the decisive set 6-2, setting up a third-round clash with Australian youngster Nick Kyrgios.