World No. 1 Rafael Nadal saved two match points to beat Viktor Troicki of Serbia 7-6(4), 4-6, 7-6(7) Saturday to book a match with Gael Monfils in the final of Japan Open tennis championships.

In 159 minutes, the top-seeded Spaniard hit 18 aces, converted two of four break point opportunities to improve his ATP World Tour-best match record to 65-8 on the season.

"The match was very close, he played well the whole time," said Nadal. "The worst part of the match was when I lost my serve serving for the match; I was not happy with how I played the last few games. But the important thing was that I got the win this time, unlike last week in the Bangkok semi-finals."

World No. 54 Troicki hit 26 aces and won 74 per cent of service points, but was unfortunate to have lost both tiebreak in the first and third set.

"It is frustrating, even if I won the second round here after being match point down," said Troicki. "I still think it was a great match from both of us." Troicki said.

In Sunday's final, Nadal will take on fifth seed Monfils, who has defeated Radek Stepanek of the Czech Republic 6-3, 6-3 in 70 minutes on Saturday to reach his 11th ATP World Tour final (2-8 record).