Roger Federer recovered from his first-match nightmare to keep alive his hopes at the ATP Finals with a comfortable victory over Dominic Thiem.
Switzerland’s 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 by Kei Nishikori on Sunday but he cut down on his errors to win.
Next up for Federer on Thursday is Kevin Anderson, who beat Nishikori 6-0 6-1 earlier in the day.
The action in London continues in the other group on Wednesday, when world number one Novak Djokovic plays Alexander Zverev, which you can watch on BBC Two (14:00 GMT) and follow with live text commentary, before Marin Cilic takes on John Isner with BBC Radio 5 live sports extra commentary online (20:00).