Madison Keys comfortably beat Jessica Pegula in straight sets on Monday to earn a spot in the US Open quarterfinals.

Keys won 6-1 6-3 against world No. 3 Pegula and reach her second straight grand slam quarterfinal -- she reached the same stage at Wimbledon earlier in the year.

Pegula had entered the tournament as one of the favorites after an impressive buildup to the tournament, but she was never able to create a head of steam against her compatriot.

World No. 17 Keys will face reigning Wimbledon champion Markéta Vondroušová in the next round.

More to follow...