Spain came from behind to beat hosts Australia 2-1 in their opening Hopman Cup tie in Perth on Sunday.
Jarmila Gajdosova gave Australia the lead in the Group B encounter with a 6-3, 3-6, 6-3 victory over Anabel Medina Garrigues in the women's singles, but third-seeded Spain, the 2010 Hopman Cup winners, hit back to level things up through Fernando Verdasco.
Verdasco, a member of Spain's Davis Cup-winning team in December, defeated former world No. 1 Lleyton Hewitt, 6-3, 3-6, 7-5. Hewitt was playing his first match since September, his absence resulting from a toe injury.
That result set up a decisive showdown in the mixed doubles and Spain emerged victorious thanks to Verdasco and Medina Garrigues in another match that went the distance.
They defeated Hewitt and Gajdosova, 6-3, 3-6, 7-6 (11/9) in front of almost 8,000 spectators at Perth's Burswood Dome.
Medina Garrigues said: "We played two hours for my singles, two hours for his singles and then the mixed doubles and it was so, so tough.
"We are very happy, so sorry for the crowd, for the country but we are happy because we can win."
Verdasco added: "I'm happy to win and also win a mixed doubles for the first time in my life, so it's pretty special and tomorrow in the morning I will practice. I cannot take the day off but I will practice early in the morning and then we will go to the beach to celebrate."
Spain is next in action against China on Tuesday, while on the same day Australia takes on France, the second seed.
Hewitt said following his return to competitive action: "I feel pretty good at the moment. Obviously we have a day off tomorrow which is nice, to just get my body right, and we play on Tuesday night again against France so we're looking forward to that."
Other results Monday at the Hopman Cup mixed teams tennis tournament on indoor hardcourts at the Burswood Dome (matches are best-of three: women's singles, men's singles, mixed doubles):
Czech Republic 2, def. Bulgaria 0
Petra Kvitova, Czech Republic, def. Tsvetana Pironkova, Bulgaria, 6-4, 6-2.
Tomas Berdych, Czech Republic, def. Grigor Dimitrov, Bulgaria, 6-4, 6-7 (8), 6-3.
Kvitova and Berdych vs. Pironkova and Dimitrov.
