Rafael Nadal warmed up for his ATP World Tour semi-final against Novak Djokovic with a 6-7 (2-7) 6-3 6-4 win over fellow Spaniard David Ferrer in his final round-robin match at the 02.
The world number four spent two hours 37 minutes on court and has a short turnaround before returning to play Djokovic at 14:00 GMT on Saturday.
Ferrer had already been eliminated from the event after two defeats.
It was the first time in 44 matches he has lost after wining the first set.
The match may have been a dead rubber in tournament terms but the lure of £109,000 - the prize money on offer for every victory in the round-robin stage - meant that there was at least a financial incentive.