Czech Republic 1 Argentina 1

World No. 20 Tomas Berdych held his nerve to prevail in a gripping encounter with Juan Monaco 6-4, 2-6, 2-6, 6-3, 6-2 and give the Czech Republic an early 1-0 lead over 2008 runner-up Argentina in Ostrava Friday.

In a match featuring 12 breaks of serve, Berdych fought back from a two-sets-to-one deficit – hitting 41 winners and putting 92 per cent of second serves into play to edge through in three hours and 27 minutes.

"If you are struggling a little bit with the best shot in your game and you don’t feel good on the court you have to really try to fight until the last point and that’s what happened today,” said Berdych, reflecting on his performance.

The 23-year-old Berdych improved to a 12-6 mark in Davis Cup singles play. The right-hander came into the tie with the confidence of last week having reached the Wimbledon fourth round, where he lost to eventual finalist Andy Roddick. The right-hander won his fifth ATP World Tour title in Munich (d. Youzhny) in May.

However, 2008 runner-up Argentina quickly hit back to level as No. 5-ranked Juan Martin del Potro dismissed Ivo Minar 6-1, 6-3, 6-3.

Playing in just his fifth Davis Cup tie, del Potro broke serve six times from 13 opportunities and with 32 winners hit more than double the total of Minar in the one-hour and 43-minute match. The 20 year old won his first ATP World Tour title at Auckland (d. Querrey) at the start of the season and was also a semi-finalist last month at Roland Garros (l. to Federer).

The Czech Republic is through to the quarter-finals for the second straight year and won the trophy in 1980 with victory over Italy. Meanwhile, Argentina is a three-time runner-up of the Davis Cup, most recently losing to Spain in the final last year in Mar del Plata – snapping a streak of 13 consecutive victories at home.

Croatia 2 United States 0

Croatian Ivo Karlovic won a five-set match for the first time in his career to defeat American James Blake 6-7(5), 4-6, 6-3, 7-6(3), 7-5 and give the host nation a 1-0 lead in dramatic fashion Friday at the World Group quarter-final clash on clay in Porec.

The 6’10’’ Karlovic struck 47 aces, just eight shy of the Open Era record of 55 he set at Roland Garros, as he overcame a nervous start to hit back in the match. The 30 year old fired 93 winners to just 31 unforced errors and broke Blake in the final game of the match to seal victory after three hours and 38 minutes.

World No. 27 Karlovic won his fourth straight singles rubber to improve to a 6-5 mark in Davis Cup. The Zagreb native is coming in on the back of two successive quarter-final efforts at The Queen’s Club (l. to Roddick) and Wimbledon (l. to Federer).

Croatia became the 12th nation to win the Davis Cup in 2005, when it defeated the Slovak Republic 3-2 in the final to become the first unseeded team to triumph in World Group history.

In contrast, the United States has won the ITF men's team competition a total of 32 times, most recently in 2007.

Marin Cilic gave Croatia  commanding 2-0 lead when he rallied to defeat Mardy Fish 4-6, 6-3, 6-7(3), 6-1, 8-6. Fish, who had been expecting to play the ATP World Tour 250 grass-court tournament in Newport, Rhode Island this week, had been called up at short notice to replace Andy Roddick, who withdrew from the tie after his punishing run to the Wimbledon final.

The U.S.A. will now look to stalwarts Bob Bryan and Mike Bryan to keep the visitors in the tie when they play Karlovic and Lovro Zovko in Saturday’s doubles rubber.