then played at the Tie Break Tens exhibition tournament in Melbourne, losing in the final to Tomáš Berdych. At the Australian Open, Nadal recorded straight-sets wins in the first three rounds, before notching a tougher four-set win against Diego Schwartzman in the fourth round. He faced Marin Čilić in the quarterfinal, but retired in the fifth set due to a hip injury. On 16 February, Nadal dropped to the No. 2 ranking after 26 weeks at the top when his rival Roger Federer overtook him in points. Nadal withdrew from the Mexican Open, Indian Wells Masters, and Miami Open due to an injury. Despite his absence in Miami, he regained the No. 1 ranking on 2 April due to Federer's second-round loss. After recovering from injury, Nadal helped secure the Spanish Davis Cup team a victory over Germany in the quarterfinal of the World Group. He beat Philipp Kohlschreiber and Alexander Zverev in straight sets. At the Monte Carlo Masters, Nadal successfully defended his title and won a then-record-breaking 31st Masters title, thus becoming the player with the most Masters titles in tennis history. It also marked his 11th title in Monte Carlo, as well as the 76th title in his career. Because he defended the points won the previous year, he kept his No. 1 ranking and began his 171st week as the world No. 1. Nadal won in Monte Carlo without dropping a set, beating Kei Nishikori in the final. Nadal went on to win his 11th title in Barcelona, defeating Stefanos Tsitsipas in straight sets, becoming the first player in the open era to win 400 matches on both clay and hard. The win marked his 20th ATP 500 series title, which put him back atop the list of most ATP 500 titles, tied with Roger Federer. It also marked his 14th consecutive season with at least one ATP 500 title. Fresh after achieving the "Undecima" at Monte Carlo and Barcelona, Nadal had to defend yet another title at Madrid. He reached the quarterfinals, defeating Gael Monfils and Diego Schwartzman in straight sets, to extend his record to 50 consecutive sets won on clay, starting from the 2017 French Open. His win over Schwartzman broke John McEnroe's record of 49 straight sets won on a single surface. McEnroe had previously achieved the record on carpet in 1984. In a surprise, Nadal lost in straight sets to Dominic