Bottom-seeded James Blake continued his imperious giant-killing run at the Tennis Masters Cup as he rallied to beat Russia's world number three Nikolay Davydenko in full sets on Wednesday at the yearend finale.

27-year-old Blake, who upset world number two Rafael Nadal 6-4,7-6 (7-0) on Monday, beat Davydenko 2-6, 6-4 and 7-5 in his second round robin match in two hours and six minutes.

Ranked eighth on the ATP rankings, the American proved nemesis for Davydenko, who lost all the five meetings against Blake including Wednesday's Masters Cup loss.

Blake also kept a clean sheet against Nadal, winning all three times after beating the Spanish sensation two days ago.

He also holds a 3-1 win-loss record against another player in his group, Tommy Robredo of Spain, sixth ranked in the world.

"It is tough to expect to beat the number two and three players in the world in consecutive matches," said Blake.

"But I realize the depth of men's tennis, going down to the top eight players, anyone can beat anyone. We are all human.

"I just try to keep my head focused, keep positive, see what happens at the end. I kept myself in the match today, hung in when Nikolay was playing unbelievable tennis.

"Then he maybe faltered just a little bit, thanks to me playing a lot better. And then I just got the momentum going at the end at the right time."

In the opening set, it was hard for both players to hold serve in the first five games until the Russian scored in the sixth game to pull away at 4-2.

While Blake, who was last qualified for the Masters Cup, did not even hold serve for once before surrendering the set at 6-2.

Blake seemed to be able to hold serve for the first time in the inception of the second set, but hawkeyed Davydenko fought off two game points by challenging the call twice in a row to force a deuce and went on to capture the fifth break.

Blake finally found the ground strokes to break twice before taking the set at 6-4.

The third set just saw a tired Davydenko struggle on each point as the American work him across the court with big serves and placement shots. Blake finally took the set and the whole match at7-5.

"After 4-2 (in the second set), I lost power and concentration because I was very tired and he got chance to make risky by return. He did." said Davydenko.

"In the third set, I try to fight but he was already better. Hegets more power."

The American might become the first to advance into the semifinals if Robredo lost to Nadal in a late Gold Group match.