By Theo Ruizenaar
ROTTERDAM (Reuters) - Top seed Roger Federer battled past Russian Nikolay Davydenko in an entertaining 4-6 6-3 6-4 triumph on Saturday to reach the World Indoor Tournament final.
The Swiss former world number one now faces third seed Juan Martin Del Potro of Argentina who brushed aside second-seeded Czech Tomas Berdych 6-3 6-1 in Saturday's first semi-final.
Federer, who has admitted struggling with the surface and his rhythm, recovered after losing the first set having been broken in the ninth game and early in the second set.
Davydenko dominated from the baseline using his powerful forehand but dropped his serve in the sixth game of the second with Federer taking four straight games to force a decider.
Davydenko wasted four break points in the third set while Federer, whose serve was never convincing, failed to take six chances before finally breaking to love to settle the match.
"We often played big matches and today again," said Federer. "It is good so see him performing so well again."
(Editing by Ken Ferris; To query or comment on this story email firstname.lastname@example.org)