Federer v Del Potro in final
Rotterdam - Top-seeded Roger Federer reached the ABN Amro World Tennis final with a hard-fought 4-6, 6-3, 6-4 win over Nikolay Davydenko on Saturday.
Davydenko made a strong start, breaking Federer in the ninth game before holding his serve to claim the first set.
The Russian forced another break in the third game of the second set but Federer broke back at 2-3 to take control.
Federer still had to overcome three break points while trailing Davydenko 4-3 in the final set.
"It's good to see Davydenko back at this playing level," Federer said. "Fortunately for me, he wasn't good enough to knock me out."
Federer, who is back in Rotterdam for the first time since clinching the 2005 title, will play third-seeded Juan Martin del Potro, who dismissed second-seeded Tomas Berdych 6-3, 6-1 to advance.
Del Potro broke the Czech in the opening game before earning another break at 5-3 to claim the first set.
The second was one-sided as the Argentine took a 5-0 lead, then surrendered a game but completed the rout on his ninth ace of the contest.
Del Potro, making his first Rotterdam appearance, will be seeking his first title since last May at Estoril.
He has beaten Federer only twice in 10 matches, and lost to the Swiss star in the Australian Open quarter-finals.