Three days of near-perfect golf had put the 36-year-old Waugh ahead of all challengers with a 7-under-par 209 headed into the final round.
After a disastrous bogey on the 11th hole and a birdie putt on the 15th, she closed the day with 1-over-par 73 for a final 6-under 282 total.
Nocera, who fired a 4-under 212 to be in joint second after three rounds, had a par round Sunday with five birdies, five bogies and one eagle on the par-5 5th. Her 282 left her tied with Waugh, necessitating a playoff.
Teeing off on hole 18, Nocera -- who turned pro and joined the Ladies European Tour in 2002 -- drove her first shot into the water and could not sink the fourth shot in the par-4 hole, handing the victory to her rival from Down Under, who hit par.
'I don't know if I deserved to win it today,' said Waugh. 'I played all right but I had a couple of bad holes.' said Waugh.
It was Waugh's third playoff after turning pro and joining the Ladies European Tour in 1991, but her first win in the do-or-die situation.
Nocera, who had her best year in 2004 -- posting three top tens and four further top 20s, and finishing fifth at the Catalonia Ladies Masters, -- owned up to nervousness.
'I really did not know if I went atop the leaderboard until I finished my round on hole 18,' she said. 'That's why I became very nervous when I had to compete in the playoff against Waugh, especially after my first drive shot went into the water.'
For her second-place finish, she took home $33,495.
In joint third place with a 5-under 283 were three Koreans Lee Jeong Eun, Hong Ran and Park Hee Young, along with Japanese amateur Shinobu Moromizato. The three professionals each received $18,304.
Copyright 2005 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.