 Complete the following phrase:  The last official tournament of the season, for Federer, was the ATP Finals in London. As the No. 3 seed, he was drawn in the group Björn Borg along with Novak Djokovic, Dominic Thiem and Matteo Berrettini. His first match was a straight-set loss to Thiem, followed by a victory in straight sets against Berretini to keep him alive in the group standings. His last group match was a straight-set win against Djokovic, his first victory against him since the 