Australian Open 2019: Frances Tiafoe beats Grigor Dimitrov to reach quarters

Frances Tiafoe has reached the quarter-finals of a Grand Slam for the first time

Frances Tiafoe celebrated his 21st birthday by reaching the Australian Open quarter-finals with victory over former semi-finalist Grigor Dimitrov.

The unseeded American beat the Bulgarian 20th seed 7-5 7-6 (8-6) 6-7 (1-7) 7-5 to reach the last eight at a Grand Slam for the first time.

The world number 39 will play world number two Rafael Nadal, who beat former Wimbledon finalist Tomas Berdych 6-0 6-1 7-6 (7-4).

"It means the world," he said.

An emotional Tiafoe took a while to compose himself after his victory, pacing the court and shaking his head, while a rendition of "Happy Birthday" rang out from the stands.

His voice cracked during his on-court interview, saying he could not believe he was in the quarter-finals of a major tournament.

"I told my parents 10 years ago I was going to be a pro tennis player and change their life," said Tiafoe, the son of immigrants from Sierra Leone.

"I worked my ass off, man."

• Frances Tiafoe: the janitor's son who became a Grand Slam hope

• Live scores, schedule and results

Tiafoe fends off Dimitrov fightback

Dimitrov had made the better start, holding his first two service games to love and carving out - but then failing to convert - four break points on Tiafoe's second service game.

But it was the American who took his chances, breaking in the seventh and 11th game before serving out the set.

Dimitrov had three set points in the second-set tie-break but Tiafoe won five points in a row to snatch it.

The Bulgarian, a former world number three who has slipped to 21st in the rankings after early exits in his past three Grand Slam appearances, raced through the third-set tie-break to stay in the match before a break in the 11th game of the fourth sealed his fate.

• Follow the Australian Open on BBC TV, radio and online

• Alerts: Get tennis news sent to your phone