Roger Federer has beaten Jo-Wilfried Tsonga in three sets to retain his ATP World Tour Finals title.
In a tight opening set, the world number four was able to snatch a break in the Tsonga serve before he claimed the set 6-3.
The Swiss found another break in the second and could have served for the match when he had a break point at 4-2, but Tsonga dug in with the help of the O2 crowd to take the set to a tie-break.
Federer seemed to be in control during the tie, but a determined Tsonga gained the momentum to overpower his opponent 8-6 and take the match to a final set.
The players remained on serve until the eighth game, which Federer broke. The former world number one then served out the match in emphatic style.
