Madison Keys claimed a straight-sets win over Alina Korneeva at the US Open, 7-5, 6-4. The key difference was serve: Keys won 42 service points to Korneeva's 30 and hit four aces to none for her opponent.
Keys edged the opening set 7-5, converting three break points while Korneeva converted two. The second set was a different rhythm, with serve broken repeatedly: Keys went up 3-1, Korneeva pulled back to 4-3, and after more exchanges Keys broke at 6-4 to close the match.
Korneeva won the return battle, 35 return points to 28, but Keys' serving proved decisive: 42 service points won against 30, and a 4-0 edge in aces. It was enough to seal the win without a tiebreak.