Roger Federer bounced back from Sunday's defeat to Dominic Thiem with a straight-sets victory over Matteo Berrettini at the ATP Finals. Knowing defeat could have ended his hopes of reaching the semi-finals, Federer prevailed 7-6(2) 6-3 to all-but dismiss debutant Berrettini's chances of qualifying from Group Bjorn Borg. Thiem faces Novak Djokovic in the other group encounter tonight at the O2 Arena, their first meeting since the Austrian won a five-set thriller in the French Open semi-finals earlier this year. Meanwhile, Federer will now prepare for a crucial match against Djokovic on Thursday – the first time the two greats have met since the latter won their classic Wimbledon final showdown in July. Federer knew he could ill-afford another slip-up going into his second meeting with Berrettini, but was heavy favourite heading into the encounter having beaten the Italian in three sets at Wimbledon in July – dropping just five games. Berrettini surpassed that tally in the opening set alone as a tight affair saw the Italian save just the one break point – which was also a set point at 6-5 – before forcing the tie-breaker. However, it was Federer who breezed through the breaker 7-2, and he took that momentum with him when breaking Berrettini in the opening game of the second set. The Swiss was edging towards victory, but not without a fight from Berrettini, who brought up three break points in a lengthy eighth game before Federer held after five deuces. The following game saw Federer bring up two match points on the Berrettini serve, and he converted the second to seal the victory in just 80 minutes.