John Isner outlasts Frances Tiafoe in five-set thriller at US Open

Isner comes to net, wins tiebreaker, roars (0:22)

John Isner comes to the net for some great shots and wins the tiebreaker to force a fourth set against Frances Tiafoe in the first round at the US Open. (0:22)

NEW YORK -- In a matchup of American tennis present and future, 31-year-old John Isner rallied from being down two sets to edge 18-year-old Frances Tiafoe in the first round of the US Open on Monday.

The 125th-ranked Tiafoe had a chance to serve out the match in the fifth set, but Isner broke back and then pulled away in the final tiebreaker to win 3-6, 4-6, 7-6 (5), 6-2, 7-6 (3) in 3 hours, 27 minutes.

It was just the second career comeback from two sets down for Isner. Tiafoe had never before played a five-set match.

The 20th-seeded Isner has finished each of the past four years as the top-ranked U.S. man and has now won 11 straight Grand Slam first-round matches. He's 5-0 against fellow Americans at majors.

Tiafoe, who got in with a wild card, has just two career tour-level wins. He had played in two previous Grand Slam tournaments, losing in the first round both times.