Open title and Davis Cup crown Nadal started 2011 by participating in the Mubadala World Tennis Championship in Abu Dhabi. In the final, he won over Roger Federer. At the Qatar ExxonMobil Open, he fell in straight sets Nikolay Davydenko in the semifinals. He and countryman López won the doubles title by defeating Daniele Bracciali and Andreas Seppi. In the quarterfinals of the Australian Open, Nadal suffered a hamstring injury against David Ferrer early in the pair's quarterfinal match and ultimately lost in straight sets, thus ending his effort to win four major tournaments in a row. In March, Nadal helped Spain defeat Belgium in a 2011 Davis Cup World Group first-round tie in the Spiroudome in Charleroi, Belgium. Nadal defeated Ruben Bemelmans and Olivier Rochus. At both the 2011 BNP Paribas Open and the 2011 Sony Ericsson Open, Nadal reached the final and lost to Novak Djokovic in three sets. This was the first time Nadal reached the finals of Indian Wells and Miami in the same year. Nadal began his clay-court season by winning the 2011 Monte-Carlo Rolex Masters with the loss of just one set. In the final, he avenged his defeat by David Ferrer in the quarterfinals of the Australian Open. Just a week later, Nadal won his sixth Barcelona Open crown, again defeating Ferrer in straight sets. He then lost to Novak Djokovic in the Italian Open and Madrid Open finals. However, Nadal retained his No. 1 ranking during the clay-court season and won his sixth French Open title by defeating Roger Federer. At Wimbledon, Nadal reached the final after three four-set matches. This set up a final against No. 2 Novak Djokovic, who had beaten Nadal in all four of their matches in 2011. After dropping the third set, Djokovic defeated Nadal in the fourth. Djokovic's success at the tournament also meant that the Serb overtook Nadal as world No. 1. After resting for a month from a foot injury sustained during Wimbledon, he contested the 2011 Rogers Cup, where he was beaten by Croatian Ivan Dodig in the quarterfinals. He next played in the 2011 Cincinnati Masters, where he lost to Mardy Fish, again in the quarterfinals. At the 2011 US Open, Nadal made headlines when after defeating David Nalbandian in the fourth round, he collapsed in his post-match press conference because to severe cramps. He again lost in four sets to Novak