Andy Murray will look to keep pace with number one rival Novak Djokovic and book his place in the semi-finals of the ATP World Tour Finals.
Having beaten Marin Cilic and Kei Nishikori, Murray only needs a set against Stan Wawrinka on Friday to guarantee his passage through to the last four at the O2 Arena for the first time since 2012.
That will not be easy in itself, with world number three Wawrinka showing much better form in beating Cilic on Wednesday than he had in his limp loss to Nishikori.
The Swiss, meanwhile, knows that a straight-sets win over Murray would maintain his record of always reaching the last four.
It may not be essential, but Murray has plenty of incentives to win his final group match - not least the knowledge that doing so would mean he could not face Djokovic until the final, setting up a straight shoot-out for world number one.
Victory would also equal the career-best winning run of 22 matches he set earlier this summer.
The Scot needed three hours and 20 minutes to see off Nishikori but was back on court early on Thursday morning for a practice session.
He said: "Obviously it's important to win matches to give yourself the best chance to go through.
"Two hundred points for each match here is quite a lot, as well. It could come down to a match between me and Novak. Who knows what's going to happen the next few days.
"Just from my side, I'll concentrate on trying to win my own matches, make it as tough as possible for Novak to jump me."
Djokovic maintained his perfect record in the group stages with a 6-1 6-2 thumping of alternate David Goffin.
After surviving tough encounters with Dominic Thiem and Milos Raonic, the Serbian heads into the last four in his best shape since winning the French Open in June.
Djokovic knows victory in the tournament would definitely be enough for him to overhaul Murray having lost top spot in the rankings to his former junior rival last week.
And there is no doubt the 29-year-old is highly motivated, replying to a reporter who suggested such an outcome would be a surprise by saying: "I have not the same perception of 'surprise' as you do. To me, that wouldn't be a surprise."
Raonic joined Djokovic in the semi-finals by beating Thiem 7-6 (7/5) 6-3 and will be the opponent for whoever wins Murray's group.
