THE HAGUE, Feb. 18 (Xinhua) -- Roger Federer won the 45th edition of the ABN Amro World Tennis Tournament in Rotterdam on Sunday by beating Bulgarian Grigor Dimitrov in the final.

Top seed Federer had no difficulties at all with second seeded Dimitrov and beat the Bulgarian, the number five on the ATP World rankings, 6-2, 6-2. It was the third tournament victory in Rotterdam for the Swiss player, after 2005 and 2012.

On Friday already Federer secured himself of the number one spot on the ATP World rankings by beating Dutchman Robin Haase in the quarter-finals. In the semi-finals Federer had beaten Italian Andreas Seppi.

Federer is now guaranteed to return as number one, officially on Monday as replacement of current number one Rafael Nadal, for the first time since November 2012. The 36-year-old Swiss also surpassed Andre Agassi, who was 33 years old when he was number one in 2003, as the oldest man to claim the world number one spot.