GSTAAD. Switzerland, July 6: A somewhat rusty Marcelo Rios struggled to overcome Bohdan Ulihrach 6-2, 6-7, 7-6 in the first round of the Swiss Open yesterday, reports Reuters..

Out of action with a thigh injury since a quarterfinal defeat by Dominik Hrbaty at the French Open five weeks ago. Rios began strongly, dominating the opening set.

But the 23-year-old Chilean soon began to show the effects of the layoff as he struggled with the high altitude at this Swiss resort, losing a second set tie-break 9-7.

In the deciding set the former world number one showed flashes of the form that helped him to clay court titles in Hamburg and St Poelten earlier this season but was still taken to a tiebreak before winning that 7-

"I feel physically fine but it was not a good match," said the

third seed. There were a lot of mishit balls, the altitude was a bit of a problem."

A return to clay also meant a return to form for Spain's Albert Costa, Morocco's Hicham Arazi, American Vince Spadea and Frenchman 'Arnaud DI

Pasquale.

First round losers at Wimbledon, the four all moved smoothly into the second round. Di Pasquale was the only player to drop a set.

Costa. Swiss Open champion in 1996, demolished Switzer-lands' Lorenzo Manta 6-1. 6-1.

The eighth seeded Spaniard, who was orushed aside in the opening round at Wimbledon by Briton Arvind Parmar, ranked 455th in the world, looked much more at home on his preferred surface, needing just 43 minutes to dispose of Manta.

Di Pasquale. Tim Henman's first victim at Wimbledon, also enjoyed his return to clay, beating French Open semifinalist Fernando Meligeni of Brazil 6-3. 5-7, 6-0.

Spadea. who reached the third round of the French Open, eliminating fifth seeded Dutchman Richard Krajicek along the way, brushed aside Italy's Renzo Furlan 6-3, 6-2 while Arazi swept past Czech Jiri Novak 6-3. 7-6.