The world number two set the tone for a dominant performance from the Swiss team when he beat Karen Khachanov 6-3, 7-6 at the Perth Arena.

Belinda Bencic then wrapped up the win for Switzerland in the Group B clash as she gave the nation an unassailable 2-0 lead by ousting Anastasia Pavlyuchenkova 6-1, 3-6, 6-3.

Bencic and Federer returned to complete the clean sweep in the mixed doubles match as they overcame Khachanov and Pavlyuchenkova 4-3, 3-4, 4-1.

"I thought the intensity was great, the level was very high too,” Federer said after his singles victory. 

“Karen got off to a great start, me too actually. 

"He put me under pressure early on and then we caught a great spell, an exhibition of serving for 45 minutes or so.

“The tiebreak was close, it was good to play that early on in the season, to play those nervy situations with the pulse up high, you’re sweating loads. 

"The match had a bit of everything, so I’m very happy with the performance.”

The United States beat Japan 2-1 in the other Group B clash to take place today.

In a contest plagued by withdrawals, CoCo Vandeweghe was awarded victory in her encounter with Naomi Osaka after the Japanese player pulled out through illness.

Osaka was replaced by 19-year-old Australian Maddison Inglis so the match could go ahead.

The US were also given a 4-0, 4-0 win in the mixed doubles as the result of Osaka's withdrawal.

World number eight Jack Sock then retired hurt when he was trailing 7-6, 1-1 in his singles clash with Yuichi Sugita.

Sock injured his hip during a fall in the first set and was unable to continue in the second, handing the Japanese player the win.

The tournament in the Australian city continues tomorrow as Canada play Germany and the hosts face Belgium in Group A.