Ten years after becoming pro, Nikolay Davydenko played his best season on the Tour in 2009, winning five titles including his maiden Masters 1000 crown in Shanghai and the very first edition of the ATP Finals in London, defeating Juan Martin del Potro in straight sets to finish the season ranked 6th.
The Russian suffered an early loss in Paris to Robin Soderling and had enough time to prepare for the elite ATP event that had moved from Shanghai to London, losing to Novak Djokovic in the repeat of the last year's final before beating Rafael Nadal and Robin Soderling for the place in the semis.
There, Davydenko faced the toughest possible rival on November 28, seeking his first victory over Roger Federer in 13 encounters and overpowering the Swiss 6-2, 4-6, 7-5 in an hour and 56 minutes for the back-to-back title matches at the ATP Finals, losing to Djokovic in 2008.
Federer had to survive a tight group with Fernando Verdasco, Juan Martin del Potro and Andy Murray but still had chances in this encounter, standing just two points away from the win in the tenth game of the final set before losing three straight games to end his run in the semis only for the second time at this event.
Davydenko served at only 54% but did his best to defend his initial shot and stay in touch with Roger, taking five points more than the Swiss and saving four out of six break points to keep the pressure on the other side of the net.
Federer's first serve worked like a charm but the second caused him troubles, having to play against five break chances and dropping serve four times and failing to reach the final for the second straight year. Roger kicked off the match with three winners in the opening game, having a chance to score an instant break in the game that followed before Nikolay repelling two break points to avoid an early setback and level the score at 1-1 after a forehand error from Federer.
The Swiss sprayed another mistake from the forehand wing to get broken in the third game, with the Russian moving 3-1 up after a service winner, finding his range and controlling the scoreboard so far. Davydenko played another rock-solid game on the return to break Roger at love and extend the gap to 4-1 before suffering a break a few minutes later as Federer finally found the way to impose his shots and draw some errors from his opponent.
Instead of reducing the deficit, Roger continued to struggle in his games, serving under 40% and falling 5-2 down after the third straight break from Nikolay who was placing his returns perfectly to take away the drive from Roger's shots.
Serving for the set, Davydenko held at 15 in game eight to grab the opener 6-2 in 30 minutes, outplaying Federer completely and moving a set away from the place in the final. With no room for further errors, Roger sailed through his service games in set number two and scored a late break at 5-4 to clinch the set and build the momentum ahead of the decider.
Unlike in the opener, Federer was able to step in and take the ball early, hitting 40% of the shots from inside the court and taking the timing off from Davydenko's strokes to forge the upper hand in the exchanges. It was all about servers in the opening nine games of the third set, with just five points lost and no deuces or break chances before Roger moved 30-0 up on the return in the tenth game, getting closer to the finish line.
Nikolay stayed focused, winning the next four points to level the score at 5-5 before his exceptional ball coverage kept him in the next game, firing a return winner that gave him a crucial break and getting a chance to serve for the triumph.
With no will to surrender, Federer created a break point with a beautiful backhand crosscourt winner that Davydenko denied with a forehand winner, earning a match point with a service winner and forcing an error from Roger to wrap up the victory, his first in 13 matches against the great Swiss!
In the final, Nikolay defeated Juan Martin del Potro to complete a perfect week and lift the biggest trophy of his career.