British number one Dan Evans set himself up for Saturday's Battle of the Brits semi-final against Andy Murray with a third win from three matches.
Evans, ranked 28th in the world, won 6-2 3-6 10-4 against alternate Ryan Peniston in their final group match.
In the other group, Kyle Edmund also maintained his 100% record with a straight-set win over Liam Broady.
Edmund, ranked 44th, will play Cameron Norrie or Paul Jubb, who meet later on Friday, in the last four.
"I played a good first set and lost a bit concentration, it was a dog fight in the end," Evans said.