English number one Dan Evans beat Kevin Anderson to set up a second-round gathering with countryman Cameron Norrie at the San Diego Open.
Evans fought through a 77-minute opening set to beat the previous world number five 7-6 (13-11) 7-5.
World number 28 Norrie beat 22nd-positioned Evans in the first round of the Australian Open recently.
Individual Briton Harriet Dart was beaten in the second round of the Chicago Fall Tennis Classic.
Dart, who beat Beatriz Haddid Maia in the wake of being added to the fundamental draw as a fortunate failure, lost 6-3 6-4 to Russian twelfth seed Veronika Kudermetova.
Evans will confront Norrie on Thursday, with Andy Murray additionally in real life against tenth seed Casper Ruud.