ATP Finals Venue: The 02 Arena, London Dates: 12-19 November Coverage: Watch live on BBC Two, Red Button, BBC Sport website and mobile app, listen on BBC Radio 5 live sports extra and follow text updates online.

Bulgaria's Grigor Dimitrov thrashed Belgian seventh seed David Goffin at London's O2 Arena to make it through to the last four on his ATP finals debut.

Sixth seed Dimitrov made it two wins out of two in the Pete Sampras Group with a 6-0 6-2 victory over Goffin.

"You get a few days out of the year that whatever you touch turns to gold, and that was the first set," said Dimitrov.

Dominic Thiem beat Pablo Carreno Busta 6-3 3-6 6-4 in Wednesday's late match.

The Austrian fourth seed will play Goffin for the other semi-final place on Friday, after seeing off Carreno Busta - an injury replacement for fellow Spaniard Rafael Nadal - in just over two hours.

"It was a really, really tight match," said Thiem. "I think he took the place of Rafa very well, a very tough three-setter. I'm pleased to be through, got very very tight at the end."

Six-time champion Roger Federer is already through to the semi-finals from the Boris Becker Group, with Alexander Zverev or Jack Sock to join him.

Thiem is still in the hunt for one of the two remaining semi-final places

Dimitrov 'humbled' by quickfire win

It took just 74 minutes for Dimitrov to sweep past Goffin and into the semi-finals as the fired-up Bulgarian was unexpectedly dominant.

"It's a special win for me," said the 26-year-old.

"My movement was great, I was reading the game really well and believing in my shots. The next thing you know the match is over. I felt I could have played more."

Both men went into the contest knowing a victory could take them through with one group match remaining, but Goffin must now produce a much better performance in his final round-robin tie against Carreno Busta on Friday.

A loud Dimitrov scream followed the deft drop volley that brought an immediate break of serve and he raced through the opening set in just 27 minutes, for the loss of 12 points.

There was little sign of a comeback when Goffin gave up another break with a double fault early in the second, and it took 48 minutes before the Belgian finally got on the scoreboard with a smash in game 10.

A brief disagreement with the umpire over a coaching violation provided the only interruption to Dimitrov's progress, and he wrapped up victory on his third match point with a thumping forehand winner down the line.

"You have days like that, you work for those days. It is nice when it comes in such an occasion, I am humbled to win that match," said Dimitrov.

"My goal was to reach the weekend, every match is very important to me. I am not here just to participate."