Roger Federer booked his place in the semifinals of the ATP Finals in London on Thursday night thanks to a 6-4, 6-3 win over Kevin Anderson in an hour and 17 minutes.
It is the 16th time that Federer has reached the semifinals of the tournament and his progress is impressive after losing his opening match in straight sets to Nishikori on Sunday.
Anderson went into the match knowing his place in the semi-finals was already assured following Dominic Thiem's 6-1, 6-4 defeat of Kai Nishikori in Thursday's opening match in the Leyton Hewitt Group, while Federer knew that result meant he only needed to win 6 games to assure his place alongside the South African.
The result leaves Federer top of the group, while Anderson will face the winner of the Guga Kuerton Group, which barring a massive surprise is likely to be Novak Djokovic.
Federer had lost to Anderson in a five-set marathon in Wimbledon, but he picked up his form from where he left off after Tuesday's impressive display against Thiem and played his best tennis of the tournament to date, dealing magnificently with Anderson's powerful serve.
Friday sees Djokovic play Marin Cilic, while John Isner will play Alexander Zverev in a repeat of the Miami Open final, which the American won and while Djokovic is assured of his place in the last four any of the other three could join him on what promises to be a fascinating day's tennis.