While Novak Djokovic, Rafael Nadal and Andy Murray continue to struggle with injuries, the evergreen Roger Federer went from strength to strength with two victories for Switzerland in the Hopman Cup on Tuesday.
Federer is using the team event as his preparation for the Australian Open in Melbourne later this month and made it four wins from four for his country in Group B.
His performances are in stark contrast to his big rivals, who have all withdrawn from tournaments due to injury this week, with Murray the latest to pull out of the Brisbane International as a result of a hip problem.
Federer got Switzerland off to a winning start on Tuesday with a 6-3 7-6 (10-8) victory over Russia's Karen Khachanov, before partnering Belinda Bencic to doubles success over Khachanov and Anastasia Pavlyuchenkova.
That doubles triumph ensured a 3-0 win for Switzerland after Bencic had earlier beaten Pavlyuchenkova 6-1 3-6 6-3 in their singles encounter.
Japan-USA struck by injuries to Osaka, Sock
Tuesday's other Group B clash saw Japan face the United States, and it was the latter who prevailed thanks to an injury to Naomi Osaka.
Osaka had to withdraw prior to her match with Coco Vandeweghe, giving the American a 6-0 6-0 triumph, while her absence for the doubles handed USA a 4-0 4-0 win.
It was the second injury of the tie after USA's Jack Sock hobbled out of his match with Yuichi Sugita with a hip problem, Sock having lost the opening set 7-6 (7-1).
With all three matches forfeited there were late calls for Maddison Inglis and Pat Cash to put on some exhibition clashes.
Inglis was comfortably beaten 7-5 6-2 by Vandeweghe, before the latter teamed up with her coach in the doubles against Inglis and Sugita – the pair representing Japan coming from a set down to win 0-4 4-3 (5-2) 4-0.