Watch | Australian Open: Djokovic fends off Tiafoe in four sets

Djokovic had only lost in the second round once at Melbourne Park, against Denis Istomin in 2017.

Melbourne: Top-seeded Novak Djokovic fended off a spirited challenge from Frances Tiafoe in the second round of the Australian Open, beating the young 23-year-old American 6-3, 6-7 (3), 7-6 (2), 6-3 in a 3 1/2-hour match.

Both players were on serve in the fourth set and looked headed for another tiebreaker when Tiafoe was given a time violation on his serve. He lost his temper and then his serve to fall behind 3-4. He didn't win another game in the match.

Though Tiafoe played an aggressive match, Djokovic was better when it mattered. He had the edge in terms of winners (56-49) and converted five break points to just two for Tiafoe.

Djokovic had only lost in the second round once at Melbourne Park, against Denis Istomin in 2017.