LONDO: David Goffin survived a shaky start to his ATP Finals shootout against good friend Dominic Thiem on Friday to win 6-4, 6-1 and advance to the semi-finals, where he has the daunting task of taking on Roger Federer.
The Belgian seventh seed lost the first three games against Austria's Thiem at London's O2 Arena but roared back to win six of the next seven and take the set.
After Thiem received medical treatment for an apparent cut on his left knee, Goffin established an iron grip on the match with an early break in the second set as his fourth-seeded opponent continued to struggle to land first serves.
The pair were playing off for the last semi-final spot after Federer, Grigor Dimitrov and Jack Sock sealed their places earlier in the week.
Goffin, who beat Rafael Nadal in his round-robin opener in the Pete Sampras group, showed impressive mental strength to bounce back from his poor start to the match after losing heavily to Dimitrov.
In the evening match Dimitrov, who has already won the group, will play Pablo Carreno Busta, who replaced world number one Nadal after the Spaniard pulled out injured following his defeat by Goffin.
Federer, chasing a seventh end-of-season trophy, topped the Boris Becker group with American Sock in second place. Sock will play Bulgaria's Dimitrov in Saturday's other semi-final.