LONDON — Grigor Dimitrov claimed the biggest title of his career and sent out a huge statement of intent as the stylish Bulgarian beat David Goffin 7-5, 4-6, 6-3, to win the ATP Finals on Sunday. The 26-year-old recovered from losing his opening two service games to finally get the better of the willowy Belgian player, but it was fiercely-fought two-and-a-half hour duel with Goffin saving four match points before finally succumbing. Dimitrov's unbeaten run this week in London earned him $2.5 million while the 1,500 ranking points have catapulted him to end an impressive year ranked third in the world — behind only all-time greats Rafael Nadal and Roger Federer. More significantly perhaps, landing the unofficial fifth grand slam appears to be proof that the former junior Wimbledon champion, once dubbed 'Baby Federer' because of his easy-on-the-eye