LONDON, Nov. 17 -- Sixth seed Grigor Dimitrov crushed alternate Pablo Carreno Busta of Spain 6-1, 6-1 to finish Group Pete Sampras play a perfect 3-0 at the ATP Finals here on Friday.

Dimitrov, playing the season finale for the first time, joins Group Boris Becker winner Roger Federer as the only unbeaten singles players, and the Bulgarian will fight for the champion berth against American Jack Sock on Saturday.

In his opening match, Dimitrov needed three sets to advance past fourth seed Dominic Thiem of Austria, but against Busta and fellow semifinalist David Goffin of Belgium, Dimitrov lost only four games in four sets.

Dimitrov, who trails Sock 1-3 in their previous four meetings, said, "Jack has been playing unbelievable, especially the past month. He's a very dangerous opponent. He has everything to beat anybody and that's why he made it out here."

In the day's other match, Seventh seed Goffin breezed past world No. 4 Dominic Thiem to reach the semifinals.

Goffin, who beat an injured Rafael Nadal in the opening match but lost to Thiem in the second, needed only 72 minutes to win 6-4, 6-1, setting up a showdown with six-time champion Roger Federer on Saturday for a place in the title match.

"I have nothing to lose," Goffin said. "He's playing so well."

Goffin has never beaten Federer in their all six meetings. They most recently played last month in the semifinals of the Swiss Indoors Basel, where Federer won 6-1, 6-2 en route to his eighth Basel title.

"I've never found a key to beat Roger. Honestly, I don't know what to do tomorrow. But I'm going to try something, something different, something that I've never done in the past. I will try to do my best to play a better match than in Basel," Goffin said.

LONDON, Nov. 17 -- Sixth seed Grigor Dimitrov crushed alternate Pablo Carreno Busta of Spain 6-1, 6-1 to finish Group Pete Sampras play a perfect 3-0 at the ATP Finals here on Friday.

Dimitrov, playing the season finale for the first time, joins Group Boris Becker winner Roger Federer as the only unbeaten singles players, and the Bulgarian will fight for the champion berth against American Jack Sock on Saturday.

In his opening match, Dimitrov needed three sets to advance past fourth seed Dominic Thiem of Austria, but against Busta and fellow semifinalist David Goffin of Belgium, Dimitrov lost only four games in four sets.

Dimitrov, who trails Sock 1-3 in their previous four meetings, said, "Jack has been playing unbelievable, especially the past month. He's a very dangerous opponent. He has everything to beat anybody and that's why he made it out here."

In the day's other match, Seventh seed Goffin breezed past world No. 4 Dominic Thiem to reach the semifinals.

Goffin, who beat an injured Rafael Nadal in the opening match but lost to Thiem in the second, needed only 72 minutes to win 6-4, 6-1, setting up a showdown with six-time champion Roger Federer on Saturday for a place in the title match.

"I have nothing to lose," Goffin said. "He's playing so well."

Goffin has never beaten Federer in their all six meetings. They most recently played last month in the semifinals of the Swiss Indoors Basel, where Federer won 6-1, 6-2 en route to his eighth Basel title.

"I've never found a key to beat Roger. Honestly, I don't know what to do tomorrow. But I'm going to try something, something different, something that I've never done in the past. I will try to do my best to play a better match than in Basel," Goffin said.