Murray found his best form of the week to beat Isner
Andy Murray won his third singles match of the week as he beat John Isner to earn Great Britain a 1-1 draw with the United States at the Hopman Cup.
Murray won 6-4 6-2 after team-mate Laura Robson suffered a third straight defeat as she lost by the same scoreline to Bethanie Mattek-Sands.
The mixed doubles was cancelled as Robson protected a tight hamstring.
Britain were out of the running for a final place having lost their opening two ties at the mixed team event.
The US will play Belgium in Saturday's final after Serbia, who had qualified from Group A on Thursday, were forced to withdraw
because of an injury to Ana Ivanovic.
It was great preparation for the Australian Open last year and now I've had three good singles matches again
France beat Italy 3-0 in Friday's other Group B tie, after Francesca Schiavone retired from her singles match against Kristina Mladenovic with a groin problem.
British hope Robson will be nursing her injury before playing in the qualifying for tournament for the Australian Open next week.
The 16-year-old Londoner recovered from losing the first three games against Mattek-Sands to make a fight of the opening set but the American's power came to the fore as she dominated the second.
Murray then produced his best performance of the week as he broke the big-serving Isner in the opening game and eased away to a comfortable victory.
"I played very well today," he said. "I returned really well and got off to a good start by breaking him in the first game, which settled me down a little.
"It can be difficult playing against someone like him when he's serving a lot of aces, and it's important to return well.
"I enjoy coming back here, it was great preparation for the Australian Open last year and now I've had three good singles matches again.
"Unfortunately we haven't played so well in the mixed, but I've really enjoyed it."
The Scot, 23, will complete his preparations at the Kooyong exhibition event next week ahead of the start of the Australian Open on 17 January.