Spain are through to the Hopman Cup final after American John Isner's injury withdrawal saw them awarded today's tie 3-0.
Fernando Verdasco and Anabel Medina Garrigues officially won each rubber 6-0 6-0 but played the tie as an exhibition against Venus Williams and unheralded Australian teenager Thanasi Kokkinakis.
Isner pulled up lame at training last night after earlier appearing on the court with his right knee strapped.
He said he was still on track to play in the Australian Open.
"I don't actually know if it's tendonitis, it's just sore and it's causing me a little bit of trouble," he said.
"I think it happened in December when I was training. I was training very hard and I might've trained too hard.
"I've always been a fast healer when I have had real injuries pop up here and there so I'm confident I'm going to be fine."
Williams capped off a strong tournament by hitting 30 winners on her way to a 6-3 6-4 exhibition win over Garrigues.
Kokkinakis acquitted himself well against former world No.7 Fernado Verdasco but was ultimately outmatched.
The 16-year-old is ranked No.756 in the world, the second-highest for his age.
He displayed a powerful service game but couldn't stop Verdasco cruising to the 7-6 (4) 6-3 victory.
Verdasco and Garrigues finished the tie strongly with a 6-1 6-3 win in the mixed doubles.
Williams said she was disappointed with the injury-spoiled end to her first Hopman Cup and missing out on the diamond-encrusted individual trophies.
"I totally wanted the ball, I don't know if you can tell," she said.
"I'm disappointed that we won't get to play one more match."
"I have to come back (to Perth), I guess that's all that means."