Federer happy to be back in mix after shock
Roger Federer recovered from his first-match nightmare to keep alive his hopes at the ATP Finals with a comfortable victory over Dominic Thiem.
Swiss great Federer, knowing defeat would mean he would not advance from his group, beat the Austrian 6-2 6-3.
The six-time champion had slumped to a shock defeat to Kei Nishikori on Sunday but he cut down on his errors to win.
Federer said: "It feels good, I'm very happy I showed a reaction after the last match against Kei.
"No match is easy here and it's not something I'm used to, losing and then coming back and playing again, but it's a great challenge and I'm happy with my attitude and how I played," he added.
Next up for Federer tomorrow is Kevin Anderson, who beat Nishikori 6-0 6-1 earlier in the day.
Meanwhile, Britain's Jamie Murray reached the doubles semi-finals of the ATP Finals in London for a third successive year. The Scot and Brazilian partner Bruno Soares beat Colombia's Juan-Sebastian Cabal and Robert Farah 6-4 6-3.