Moscow:Nikolay Davydenko defeated Paul-Henri Mathieu 7-5, 7-6 (9) to win his second straight Kremlin Cup title on Sunday, and Elena Dementieva rallied to upset fourth-seeded Serena Williams for the women's crown.
Dementieva won 5-7, 6-1, 6-1 to win her hometown tournament on the third attempt.
It was the first title this season for the fourth-ranked Davydenko, the top seed who also won here in 2004.
Davydenko broke the fourth-seeded Mathieu in the fifth game of the first set. But the Frenchman, who won here in 2002, leveled at 4-4 before the Russian got a decisive break with a smash in the 11th game.
"I had my chances in the first set but missed them," said Mathieu. "This match was decided by just two or three points which I failed to win."
A break down in the second set, Mathieu saved two match points before making it 5-5. Davydenko then saved two set points in the 12th game to force a tiebreaker, and closed the match on his fourth match point with a backhand down the line.
"I'm really happy to win today," Davydenko said. "Psychologically it was my most difficult win at the Kremlin Cup."
An erratic Williams, who fired seven aces, struggled at the beginning and made 59 unforced errors.
Serving in the opening game, Williams fell behind 40-love but rallied and served two aces on deuce to hold. Down 40-15 on her next serve, she returned long to fall behind 2-1.
But the American then won three consecutive games before the Russian broke back to level 4-4. Williams broke Dementieva at love in the 12th to go up in the match.
Dementieva - runner-up in 2001 and 2004 - won four straight games in the second set.
Williams blamed herself for her poor game.
"I made a lot of errors," Williams said. "It was me. Every ball I hit I felt was out. It was so frustrating."
Williams broke in the third set but then lost six consecutive games. Dementieva closed the match when Williams returned wide.
"She (Dementieva) played really unbelievable," said Williams. "She should try to play like that more often."
Dementieva said she was helped by playing in Moscow.
"It's an incredible feeling when you win at home," said Dementieva. "I knew that if I did not beat Serena today, it would never happen again. I just stepped on the court and played my tennis."
It was the eighth career title for the 14th-ranked Dementieva, who had not beaten Williams in four previous matches.
Williams, ranked seventh, had not dropped a set on the way to her third final this season. She was playing in Moscow for the first time in a decade. In 1997, the 16-year-old Williams qualified and lost in the first round when she was ranked 448th.