In a preview of what was to come on the day, Sloane Stephens and Madison Keys kicked off the U.S. Open with a three-set thriller won by Stephens 6-3, 1-6, 7-6 (7) in two hours, ten minutes on Arthur Ashe Stadium.
Having played in the championship match in 2017, the American duo, best friends, have seen their rankings slip for various reasons which caused them to play on the tournament's first day.
Keys took the initiative, racking up 36 winners, but also committing 37 unforced errors to Stephens' 25. She took the first set behind an early break, but watched as Keys won eight of the next ten games.
The match would eventually be decided in a third-set tiebreaker which Stephens won, improving her record against Keys to 5-2, to reach the second round, where she will face another American in 21st seed Cori Gauff.
Stephens gets the better of Keys in first-round tussle
It was Stephens who saved three break points in her opening service game of the match and when Keys flew a backhand long on break point in her own service game after holding a 40-15 lead, Stephens led 2-1.
The 2017 champion was pushed to deuce in the sixth game, but came through the game after a pair of unforced errors by Keys, to make it 4-2. Three games later, she wrapped up the set after Keys just missed on a backhand.
The second set was a runaway as Keys broke with a forehand volley winner, broke a second time after Stephens sent a forehand wide for a 3-0 lead claimed the set on a slice backhand approach to level the match at one set all.
In the third and decisive set, Stephens saved a break point in the fifth game and Keys fended off a pair of break chances in the ninth game. Stephens served for the match leading 6-5 only to see Keys break and force a tiebreaker.
Keys won three straight points midway through the breaker to go in front 5-3, but Stephens rallied and although she let two match points slip away, she converted on her third chance when Keys flew one final backhand wide.