Grigor Dimitrov has underlined his title intentions with a commanding straight-sets win over David Goffin at the ATP World Tour Finals in London.

The Bulgarian booked his place in the semi-finals on debut with a 6-0 6-2 victory, after opening the tournament with a three-set win over Austrian Dominic Thiem.

Dimitrov’s masterclass came less than 48 hours after Goffin enjoyed the biggest win of his career against world No.1 Rafael Nadal.

“You get a few days in the year when everything you touch turns into gold, I had one of those today,” Dimitrov said.

“But I work for those days. It’s very nice when they come on such an occasion.

“I’m very humbled to win that match. I just wanted to come out and compete today.

“It’s just a special win for me.”

At one point, after winning the first nine games of the match, the Australian Open semi-finalist threatened to record just the second 6-0 6-0 rout in the 47-year history of the season-ending showpiece.

Goffin, though, rallied to avoid taking an unwanted place in the history books alongside Gaston Gaudio, Argentina’s former French Open champion who suffered the ignominy against Roger Federer in the 2005 semi-finals in Shanghai.

But Goffin’s heavy defeat has done little to boost his semi-final prospects – and also brings first alternate Pablo Carreno Busta into the equation.

Carreno Busta has replaced the injured Nadal in their four-man pool, with the Spanish world No.1’s countryman scheduled to play Thiem in the night match later on Wednesday at the indoor O2 Arena.

Victories over Thiem and Dimitrov, in his second round-robin match, and a Thiem win over Goffin on Friday would propel Carreno Busta into the last four.

Like Dimitrov, Federer is also through to the semi-finals as he chases a record-extending seventh season-ending crown.

German world No.3 Alexander Zverev and American Jack Sock, the tournament’s last and eighth qualifier, clash for a semi-final spot on Thursday night.

Federer takes on winless Croat Marin Cilic in Thursday’s first match.