In 2009, he was granted a wildcard to the main draw of the ABN AMRO World Tennis Tournament and scored an upset over then world No. He was granted a wildcard to the main draw of the Open 13, but lost to world No.
23 Tomáš Berdych, earning his first ATP main draw win. 8 Gilles Simon in the first round, despite serving for the match at ninth game of the third set.
He bounced back a week later by qualifying at the Honolulu Challenger, but lost to Donald Young in the second round.
Dimitrov then participated for Bulgaria in the Davis Cup, claiming all 3 wins in a 3–2 victory over Monaco.
Dimitrov began dating Maria Sharapova in late 2012.
He and Sharapova only confirmed their relationship after the 2013 Madrid Open where the Bulgarian managed his first win against a world No. At the beginning of 2016, he started dating Nicole Scherzinger, 13 years his senior, in a discreet relationship.On his way to the title he also defeated top seed Tsung-hua Yang of Taiwan in the semifinals. In 2008, Dimitrov began frequent participation in men's events.After the tournament Dimitrov announced that he was ending his junior career and focusing on improving his ATP ranking. His first title came on clay at a futures tournament in Barcelona.He reached the quarterfinals of the challenger Open Castilla y León losing out in three sets to Marcel Granollers.He then lost in the second round to Martin Fischer in straight sets at the American Express – TED Open.The victory saw him join former junior champions Roger Federer and Stefan Edberg and guaranteed him a wildcard entry into the 2009 Wimbledon men's draw.His success continued at the US Open, which he won on 7 September, defeating American qualifier Devin Britton in two sets.His first ATP level match was at the Ordina Open where he lost to Igor Andreev in straight sets.After his junior US Open title he won back to back futures tournaments in Madrid on hard court and rose 300 places to career high ranking of 477.He reached the 2nd round of the Aegon Championships after defeating Iván Navarro, but lost in two tiebreaks to Gilles Simon.In Wimbledon where he got a wildcard as the 2008 Juniors Champion he won the first set of his first round match against Igor Kunitsyn but then suffered a knee injury.