Petra Kvitova saved two match points before completing a remarkable third set comeback to defeat Garbine Muguruza and reach the the last 16 of the US Open on Saturday.

The Czech 21st seed looked to be heading for elimination as she trailed 5-2 in the third after the opening two sets were shared.

But the two-time Wimbledon champion rallied superbly to level at 5-5 and then fought off two Muguruza match points at 5-6 before holding to force a tie break and sealing a 5-7, 6-3, 7-6 (12/10) victory at the Arthur Ashe Stadium.

Kvitova said she had drawn inspiration from Serena Williams' defeat on Friday night, when the 23-time Grand Slam champion saved five match points before eventually being eliminated.

"I watched Serena last night and it was amazing how she was saving match points, so I tried to do the same today," Kvitova said.

"It was a great match, a great fight. She was serving very well and I was dealing with nerves," the 32-year-old added.

Kvitova, whose best performances at the US Open were quarter-final appearances in 2015 and 2017, will play either Jessica Pegula of the USA or China's Yuan Yue in the fourth round.