Tennis-Del Potro puts Argentina level with Czechs in Davis Cup

OSTRAVA, Czech Republic, July 10 (Reuters) - Juan Martin Del Potro cruised past Ivo Minar in straight sets to put Argentina level at 1-1 with the Czech Republic in their Davis Cup World Group quarter-final on Friday.

Argentina, led by world number five Del Potro in the absence of the injured David Nalbandian, saw their chances improve after Czech Radek Stepanek was left out of Friday's singles due to a knee problem.

However, the Czechs took the lead in the tie when world number 20 Tomas Berdych overcame Juan Monaco 6-4 2-6 2-6 6-3 6-2 after three hours and 27 minutes in a tough opening match.

"I had problems with first serves. Then it improved and the last two sets were clear," Berdych said.

Del Potro then stifled Davis Cup newcomer Minar in the second match, taking an hour and 43 minutes to win 6-1 6-3 6-3.

"My serve was very good and that was key," Del Potro said.

On Saturday, Czechs Stepanek and doubles specialist Lukas Dlouhy will team up to take on Del Potro and Leonardo Mayer before the decisive singles matches on Sunday.

However, Berdych did not rule out playing instead of Dlouhy and team captain Jaroslav Navratil said it would depend on how the Czech top player feels after his tiring first match.

Stepanek has not been nominated for the final singles rubber against Monaco on Sunday but team doctor Pavel Kolar said the world number 21 should be fit enough to play instead of Minar.

"He should be playing (on Sunday) but this (Saturday's) match will hint at how his injury will develop," Kolar said.

Three times runners-up Argentina are trying to reach their sixth semi-final in eight years, after beating the Netherlands 5-0 in the first round.

The Czechs, who lost by the same margin to Argentina in their last encounter in 2005, have not won the Davis Cup since 1980 when they were still part of Czechoslovakia.

However, the Czechs, mainstays in the World Group in recent years, have beaten favourites such as the United States and Spain in past competitions.

(Reporting by Martin Dokoupil, Editing by Ken Ferris)