They beat top seeds Bob and Mike Bryan in the final.
In April 2012, Serbia's Janko Tipsarević defeated him in five sets to level the Davis Cup quarterfinal at 1–1, after a stormy five-hour match.
At that point, he achieved a career-high ATP world ranking of No. Earlier in 2006, he won his first ATP singles title, beating Christophe Rochus in Rotterdam, but he had yet to progress beyond the third round of a Grand Slam tournament until he got into the quarter-finals at Wimbledon beating Frank Dancevic, Xavier Malisse, Juan Carlos Ferrero and Fernando Verdasco, before he was eliminated by 34-year-old Jonas Björkman, after holding match point at 7–6 in the fourth-set tie-break.
This performance helped Štěpánek break into the top 10 and achieve his highest world ranking of no. However, after Wimbledon, Štěpánek was out of action for the rest of the year due to a chronic neck injury.
Štěpánek first came to mainstream notice when he defeated former World No.
1 Gustavo Kuerten in five sets on his way to the third round of the 2003 Australian Open.
Then, at the Australian Open, he made it to the third round and was overpowered by Verdasco in straight sets.
However, he continued his winning streak, emerging victorious, 6–3, 6–3, to place himself in the first semifinal against Robin Söderling, where he lost.
Štěpánek exited the 2011 French Open in the first round, losing in straight sets to Frenchman Richard Gasquet.
In the 2008 Summer Olympics, he lost to Michaël Llodra in the first round in three sets. 27, but attended the year-end Masters Cup as an alternate.
He was vacationing in Thailand and so was able to come to the tournament held in Shanghai without delay.
In the second round of the 2007 US Open, Štěpánek played a match against third seed Novak Djokovic, which he ended up losing after 4 hours and 44 minutes of play in a fifth-set tiebreak.