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 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.
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 Djokovic in the final. After the US Open, Nadal made the final of the Japan Open Tennis Championships. Nadal, who was the 2010 champion, was defeated by Andy Murray. At the Shanghai Masters, he was upset in the third round by No. 23 ranked Florian Mayer. At the 2011 ATP World Tour Finals, Nadal was defeated by Roger Federer and Jo-Wilfried Tsonga in the round-robin stage, and was subsequently eliminated from the tournament. In the Davis Cup final in December, he helped Spain win the title with victories over Juan Mónaco and Juan Martín del Potro.
In the 2011 Wimbledon final, Djokovic won in four sets for his first Grand Slam final victory over Nadal. Djokovic also defeated Nadal in the 2011 US Open Final. In 2012, Djokovic defeated Nadal in the Australian Open final for a third consecutive Grand Slam final win over Nadal. This is the longest Grand Slam tournament final in Open era history at 5 hours, 53 minutes. Nadal won their last three 2012 meetings in the final of the Monte Carlo Masters, Rome Masters and French Open in April, May, and June 2012, respectively. In 2013, Djokovic defeated Nadal in straight sets in the final at Monte Carlo, ending Nadal's record eight consecutive titles there, but Nadal got revenge at the French Open in an epic five-setter 9–7 in the fifth. In August 2013, Nadal won in Montreal, denying Djokovic his fourth Rogers Cup title. Nadal also defeated Djokovic in the 2013 US Open Final.
Nadal and Andy Murray have met on 24 occasions since 2007, with Nadal leading 17–7. Nadal leads 7–2 on clay, 3–0 on grass, and 7–5 on hard courts (including 4–4 on outdoor courts, but Nadal leads 3–1 on indoor hard courts), but trails 1–3 in finals. The pair once met regularly at Grand Slam level, with nine out of their 23 meetings coming in Grand Slams, with Nadal leading 7–2 (3–0 at Wimbledon, 2–0 at the French Open, 1–1 at the Australian Open, and 1–1 at the US Open). Seven of these nine appearances have been in quarterfinals and semifinals, making the rivalry an important part of both men's careers. Nadal defeated Murray in three consecutive Grand Slam semifinals in 2011 from the French Open to the US Open. They have never met in a Grand Slam final, but Murray leads 3–1 in ATP finals, with Nadal winning at Indian Wells in 2009 and Murray winning in Rotterdam the same year, Tokyo in 2011, and Madrid in 2015.
After a long span of injuries with both players, the pair met in a Grand Slam for the first time since the R16 at Wimbledon in 2011 at the 2017 US Open. Del Potro, facing Nadal after a victory in 4 sets against Federer, made it to the SF of a Grand Slam for the first time since 2013. However, the Spaniard got the better of him in that encounter, beating Del Potro in 4 sets. The pair then met in 3 of the 4 grand slam events in 2018, including a memorable match at the 2018 Wimbledon QF. The match went on for close to 5 hours, with Nadal coming out on top, 7–5, 6–7, 4–6, 6–4, 6–4. The pair had another meeting at the 2018 US Open, during which Nadal was forced to retire against Del Potro in the SF. Del Potro then went on to his first grand slam final since his victory in the 2009 US Open. He ended up losing in the final in straight sets to Novak Djokovic.
Nadal's autobiography, Rafa (Hyperion, 2012, ISBN 1-4013-1092-3), written with assistance from John Carlin, was published in August 2011. Nadal has been in a relationship with María Francisca (Mery) Perelló Pascual (often mistakenly referred to as Xisca in the press) since 2005, and their engagement was reported in January 2019. The couple married in October 2019.