Flavia Pennetta booked her place in the quarter-finals of the US Open with a dramatic straight sets victory over China's Peng Shuai.
The Italian, who knocked out Maria Sharapova in the previous round, secured the first set 6-4.
Serving for the match at 6-5 in the second, the number 26 seed seemed affected by the New York heat, and Peng took the set to a tie-break.
The world number 14 was ahead 5-0, then 6-2, before Pennetta clawed herself back into the set to win 8-6 and set up a last-16 tie against Germany's Angelique Kerber.
