Norfolk has claimed some big wins over Wagner this year
Paralympic champion Peter Norfolk clinched his second US Open quad singles title with a three-set win over world number one David Wagner.
The Briton won 6-3 3-6 6-3 to win his second Grand Slam title of 2009 and his 16th wheelchair tennis major.
"I'm absolutely delighted to have had the chance to defend my title," said the 48-year-old from Hampshire.
"It's been a difficult few days with the rain and it was a see-saw match, which I'm glad to have closed out."
Norfolk began slowly and lost his opening serve game against his American opponent.
But he recovered to win the next four games to move 4-2 ahead, going on to convert his first set point.
Wagner earned the decisive breakthrough of the second set, breaking the Norfolk serve to go 5-3 ahead and serving out comfortably to level the match.
The players exchanged breaks at the start of the deciding set before Wagner went 3-2 up.
But Norfolk, who won the Australian Open earlier this year, reeled off the next four games to add to his victory in the inaugural US Open quad singles event in 2007.