NEW YORK - Czech Petra Kvitova sent across 14 aces to down Spanish ninth seed Garbine Muguruza 5-7 6-3 7-6(10) in a thrilling third-round duel at the US Open on Saturday.

Kvitova was in good form headed into Flushing Meadows after reaching the Cincinnati final and reiterated her claim as one of tennis' great fighters when she saved match point twice late in the third set to push the affair into the tiebreak.

Muguruza, who suffered first-round exits from Wimbledon and Roland-Garros before pulling out of August's Silicon Valley Classic with an injury, was not at her fighting best as she sent over 21 winners to 43 from her opponent across the match.

The twice Grand Slam winner pulled out every weapon in her arsenal to defend three match points in the tiebreak but was forced to endure another heartache this year when she whacked the ball into the net on the final point.

"She was serving very well and I was dealing with the nerves a little bit as well," twice Wimbledon champion Kvitova said after the match, having improved her career record against Muguruza to 6-1.

"I do feel the love from you fans... I had a great week before coming here in New York so it's helping me as well." REUTERS