Jamie Murray and Bruno Soares are within sight of the doubles semi-finals after beating Americans Bob and Mike Bryan at the ATP World Tour Finals.
The Briton and his Brazilian partner won 6-3 6-4 to top their group at London's O2 Arena.
Murray and Soares must wait for the result of the evening match to see if they have qualified with one round-robin match remaining.
Treat Huey and Max Mirnyi play Ivan Dodig and Marcelo Melo at 18:00 GMT.
Any result other than a two-set win for Dodig and Melo will ensure Murray and Soares reach the last four.