Argentina advanced to the Hopman Cup team tennis final when Germany’s Tommy Haas withdrew from his singles match against Gillermo Coria because of a strained groin and defaulted the mixed doubles.

Anna-Lena Groenefeld had given Germany a 1-0 lead when she rallied for a 3-6, 6-2, 6-1 win over Gisela Dulko in the women’s singles match.

Haas took the first set off Coria but then retired after receiving treatment, handing the Argentine a 5-7, 3-2 win.

Unbeaten Argentina clinched top spot in Group A and a place in a Hopman Cup final for the first time. Germany finished second after earlier wins over Russia and Italy.

Assistant tournament director Rob Casey confirmed Haas’ injury and said the German would go for medical scans today.

A similar problem forced Australia’s Mark Philippoussis out and threw Group B into confusion earlier yesterday, when Slovakia upset the United States.

Daniela Hantuchova defeated Meghann Shaughnessy 6-4, 6-2 and Dominik Hrbaty beat James Blake 7-6 (2), 6-4 to give Slovakia an unbeatable 2-0 lead going into the mixed doubles match.

In the doubles, Americans Blake and Shaughnessy lost the first set in 17 minutes, before saving five match points in the second set and coming back to win 0-6, 7-6 (13), 10-7 in a super tiebreaker.

The Americans weren’t told before the mixed doubles that they’d be out of contention for Saturday’s final if they lost 3-0 to Slovakia.

There was some confusion over the status of today’s United States vs. Australia group match after the hosts drafted Paul Baccanello in to partner Alicia Molik.

Philippoussis hurt his right groin in a loss to Dutchman Peter Wessels on Wednesday night and then skipped the mixed doubles, giving the Netherlands an unexpected 2-1 win over Australia.

Organisers said Australia was out of contention for the final, yet Shaughnessy and Blake still have to beat Baccanello and Molik to remain in the finals race.

All four teams in Group B have a win and a loss apiece going into the last round-robin encounters. If, as expected, the Americans beat Australia, that will leave two teams with 2-1 win-loss records and the No. 1 position will be decided on a countback.

Blake and Shaughnessy might have expected they’d get a walkover against Australia after Philippoussis pulled out.

But Hopman Cup spokeswoman Rosita Stangl said organisers couldn’t hand the United States a straight walkover because every singles and doubles outcome went to determining group positions when a finals place is at stake.

“I think it’s a good thing we didn’t know that before the match,” said Shaughnessy. “We were a bit disappointed with our singles, but obviously glad to pull it out in the doubles.”

Hrbaty said he’d booked his flight for the next tournament after an opening loss to Australia, but now had to change his plans to stick around in Perth.

“For sure it’s a great feeling,” Hrbaty said. “We’re maybe a little lucky Philippoussis got injured. I had my flight booked, but now I’ll have to change that because we’re a chance for the final.”