WATCH: Tiafoe gets emotional after reaching Oz quarters

On his 21st birthday, Frances Tiafoe took out Grigor Dimitrov at the Australian Open to move on to his first Grand Slam quarterfinal. The American produced another emotional celebration after he won in four sets, ripping off his shirt and beating his biceps and chest while yelling into the crowd.

Before this tournament, the best the American has done in a Grand Slam was last year's Wimbledon when he fought to the third round.

The emotions continued in the world No. 39's on-court interview where Tiafoe was moved to near tears by what he had accomplished this week.

The youngster's greatness on the court has paid off big time by allowing him to repay his family, who helped him get to this grand stage all the way from humble beginnings in Maryland.

"[In] 2017, in March, bought a house there, bought a house in Maryland for my mom. My dad is in an apartment in Orlando," Tiafoe said. "So, yeah, that was big. Getting us out of—you know, just put us in better situations. I was able to do stuff like that. At the beginning, that was just my goal as a kid. I didn't want to go to college. I knew that from a young age. I wanted it and I'm doing it."

In the quarterfinals, Tiafoe will have his biggest challenge yet in Rafael Nadal. But he isn't afraid, offering advice to the Spaniard with only four words: "He better get ready."

Tiafoe will have to figure out even bigger celebration if he takes out the world No. 2. After beating No. 5 seed Kevin Anderson, the American put on a bicep-slapping display.

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