at the Australian Open. In the first round, he retired after the second set because he felt physically "empty". In April 2017, Haas won his first match at ATP-level in 21 months in Houston. At the age of 39, he defeated the almost 20 years younger Reilly Opelka in the first round. This victory made him the oldest player to win an ATP Tour match since Jimmy Connors in 1995. He then lost to top seed Jack Sock in three sets. At the Monte-Carlo Masters, Haas beat world No. 40 Benoît Paire in straight sets in the first round. In the second round, he lost to Tomáš Berdych in a close match. In June, Haas reached the quarterfinals of the MercedesCup in Stuttgart after upsetting Roger Federer in the second round and Pierre-Hugues Herbert in the first round. In the quarterfinals, he lost to sixth seed Mischa Zverev in straight sets. Haas played his last ATP tournament in Kitzbühel in August 2017, where he lost in the first round to compatriot Jan-Lennard Struff. He was not given a wild card for the US Open and cancelled his participation at the Vienna Open. 2018 At the 2018 Australian Open, Haas coached Lucas Pouille. In February, it was assumed that Haas ended his career because of an interview he gave a California newspaper. On 15 March 2018, he officially announced his retirement from the ATP World Tour. Performance timelines Singles * 2007 Wimbledon counts as 3 wins, 0 losses. Roger Federer walkover in round 4, after Haas withdrew because of a torn stomach muscle, does not count as a Haas loss. 1Held as Hamburg Masters until 2008, Madrid Masters (outdoor clay) 2009 – present. 2Held as Stuttgart Masters until 2001, Madrid Masters (indoor hard) from 2002 to 2008, and Shanghai Masters 2009 – present. Doubles 1Held as Hamburg Masters until 2008, Madrid Masters (outdoor clay) 2009 – present. 2Held as Stuttgart Masters until 2001, Madrid Masters (indoor hard) from 2002 to 2008, and Shanghai Masters 2009 – present. Post-retirement activity In July 2020, Haas played the Berlin tennis exhibitions, where he beat Jan-Lennard Struff before he lost to Dominic Thiem. Playing style Haas was an all-court player, capable of playing well on clay, hard, and grass surfaces. Nick Bollettieri noted Haas as having "one of the greatest backhands in the world", praising its versatility and power. Haas also possessed a powerful slice