Pegula moves into last 16 of US Open

American third seed Jessica Pegula fought off Ukraine's Elina Svitolina in three sets to clinch her place in the last 16 of the US Open on Saturday.

Pegula broke twice in the final set to brush the 26th-ranked Svitolina aside and seal a 6-4, 4-6, 6-2 victory.

"I knew no matter what she wasn't going to go away," said Pegula, a quarter-finalist at five of the past seven Grand Slams.

She beat Svitolina for the fourth time in a row, having also defeated her in three sets in Washington last month.

"I feel like every time I play her it's so close. She definitely picked up her level and forced me to come out strong in the third."

The 29-year-old Pegula will play compatriot and 17th seed Madison Keys for a place in the quarter-finals.