Kenin broke for 3-2 to take it 6-4.
Kostyuk broke for 5-3 and held for 6-3, clinical after saving break points in holds for 1-0 and 4-3, while Kenin could not convert.
Kenin broke for 2-0 but Kostyuk broke for 2-3, 5-4 and 6-5, surviving a 7 minute deuce hold for 3-3 saving both break points before Kostyuk held for 7-5.