By Zoran Milosavljevic

BELGRADE (Reuters) - Janko Tipsarevic upset Wimbledon 2010 finalist Tomas Berdych to pull Serbia level with the Czech Republic after the first day of their Davis Cup world group semi-final on Friday.

Tipsarevic outgunned Berdych 7-5 6-2 2-6 7-6 to take the score to 1-1 after Czech Radek Stepanek had fought back from a set down to beat Viktor Troicki, who stood in for the ill and exhausted Novak Djokovic, 4-6 6-2 6-4 6-4.

Under pressure after Troicki lost his match and facing a rival 30 places above him in the ATP rankings, Tipsarevic produced outstanding tennis to down world number seven Berdych after three hours 38 minutes.

"It was a great atmosphere and I am glad the fans got behind me when I needed their support most," Tipsarevic said in a courtside interview after coming back from a break down in the fourth set.

"The opening day has shown that Serbia is still a good team even if Djokovic has to take a day off, while we are one of the best teams in the world with him," he told a news conference after getting a standing ovation from the fans.

World number two Djokovic, who was exhausted on arrival in Belgrade from New York late on Wednesday after he lost the delayed U.S. Open final to Rafael Nadal, said he hoped to be fit for Saturday's doubles or Sunday's reverse singles.

"I would have done the same if Troicki had won because it's the only way to beat a top-ten player like Berdych."

The Serbian took the opening two sets with a flurry of forehands down the line, backhand returns and cross-court winners which left Berdych bedazzled.

He appeared to run out of steam after the Czech adopted a more aggressive approach to take the third set and a 3-1 lead in the fourth, but regained his composure to break back straight away and force a tie-break.

Berdych, who turned 25 on Friday, fought back from 5-2 down to reach 6-5 but failed to hold his nerve and blasted a forehand wide to send the home fans into raptures.


Troicki was thoroughly outplayed by Stepanek after winning the opening set.

Roared on by a small band of vociferous Czech fans among 15,000 home supporters in the Belgrade Arena, Stepanek tormented his rival with a series of forehand winners and sliced dropshots.

Stepanek converted five of his seven break points and 24 of his 29 net points, while Troicki made 50 unforced errors, including a wide backhand down the line which handed Stepanek victory after three hours.

"I expected to play Djokovic and not Troicki so I had very little time to adjust and prepare a different strategy, hence I am very pleased with my performance," said Stepanek.

Troicki said: "This is one of the most painful defeats of my career. I can't explain what happened after the opening set, I just lost my rhythm and focus."

Serbia's doubles specialist Nenad Zimonjic is certain to play on Saturday but team captain Bogdan Obradovic faces a dilemma over who to put alongside him.

"We have to think it over, it will probably be a last-minute decision because we have several good players at our disposal to team up with Zimonjic," he said.

The Czechs are hoping to reach their second successive final after losing to Spain last year, while Serbia are aiming for their first after getting into the competition's top tier for the first time in 2008.

In the final, the winners of the Belgrade tie will play either France or Argentina who were meeting in Lyon, with the French leading 2-0 after Friday's opening day.

(Editing by Clare Fallon)