The 22-year-old eased to a 6-1, 7-6 victory over Davide Sanguinetti to level the round-robin tie at 1-1 after Francesca Schiavone had beaten Gisela Dulko 6-1, 6-3 in the opening match of the mixed team event.

Coria and Dulko then teamed up to beat the Italian pair 7-5, 6-0 and put the fourth seeds in pole position in Group A.

"I had to run everywhere today (in the singles) but I am very happy and it was a fun game," said Coria, whose comments were translated by Sanguinetti.

"I am also very happy to win my first mixed doubles match and it is really good to be here in Perth."

For Coria, runner-up at the French Open last year, his singles victory was his first since Wimbledon last June, where he was beaten in the second round.

Shoulder surgery in August kept him off the tour for almost four months but having lost all three of his matches on his return in November at the Masters Cup in Houston, Coria looked more like his usual self on Sunday as he eased to victory against the 110th ranked Sanguinetti.

The Italian also had to deal with an ankle injury, which he picked up while stretching for a backhand in the second game of the match.

After taping his ankle at the next change of ends, Sanguinetti battled on and though he dropped the first set, he led 4-2 in the second before Coria recovered to clinch victory.

The win was especially sweet for Coria, who was due to participate in the 2002 tournament but was prevented from playing after he received a seven-month ban for returning a positive drugs test for nandrolone.

Earlier, Schiavone proved too consistent for Dulko as she wrapped up victory in one hour, five minutes.

The Argentine, who beat Martina Navratilova at the French Open and Wimbledon last year, made 46 unforced errors.

But the 19-year-old made amends with a fine performance in the deciding mixed doubles as she and Coria secured victory for Argentina.

"I was a little nervous in the singles and it was difficult because it was the first match of the year," Dulko said.

"But I played much better in doubles and am very happy now.

"It was good to play with Guillermo but I think he wins too many singles matches to play doubles."

Top seeds Russia, represented by Marat Safin and Anastasia Myskina, begin their title campaign on Monday against Germany, also in Group A, while Group B begins with a match between host nation Australia and the Slovak Republic.

The United States open the defence of their title on Tuesday with a Group B clash against the Netherlands.