NEW YORK (Reuters) -Former champion Sloane Stephens overcame best friend Madison Keys's aggressive play to secure a 6-3 1-6 7-6(7) win in the first round of the U.S. Open on Monday.

The 2017 winner quickly took control of the first set on Arthur Ashe Stadium, putting up a strong defensive performance to fend off three break points as Keys committed 15 unforced errors.