PORTLAND, September 2, 2013 (AFP) - Pettersen finished with a 20-under par total of 268 at Edgewater Country Club on Sunday, adding a second Safeway Classic crown to the one she won in 2011 when the tournament was held at Pumpkin Ridge.
"Very glad to pull this one off," said Pettersen, who notched the 12th LPGA title of her career and her second in 2013.
American Stacy Lewis fired a four-under par 68 on Sunday to finish second on 18-under 270, completing all four rounds without a bogey.
"You would think if you went bogey-free you would win the golf tournament," Lewis said. "It's just you're making so many birdies out here and everybody is scoring so low, unfortunately that's kind of the way it is."
Former world number one Tseng, who took a three-shot lead into the final round, saw her bid to end a 17-month victory drought evaporate early with a double-bogey at the par-three second hole followed by bogeys at the third and fourth.
The Taiwanese star, who reigned as number one for 109 straight weeks, finished with a six-over 78 to share ninth place on 276. She remains in search of her first LPGA title since March of 2012.
Pettersen also made a double-bogey five at the second, but she responded with eight birdies in the next 11 holes -- including four birdies in a row starting at the fifth.
"I decided before I went out just not have too many reactions, good or bad," said Pettersen, part of the European Solheim Cup team that earned their first-ever victory on US soil with a triumph over the Americans in Colorado in August.
"I knew there were birdies out there if you really get it going. I just tried to put it behind me. It was a disaster of a hole, 150 yards."
World number three Pettersen, who won the LPGA Lotte Championship in Hawaii in April, became the fourth player on the LPGA Tour to record multiple wins in 2013.
World number one Park In-Bee, a late withdrawal from this field, has won a remarkable six titles that include three majors. Lewis has won three titles and Spain's Beatriz Recari has won two.
American Lizette Salas, runner-up to Pettersen in the Lotte Championship in a playoff, finished third, carding a 69 for 271.
US veteran Cristie Kerr carded a second straight 69 for sole possession of fourth place on 272, AND Germany's Caroline Masson boosted her bid for LPGA rookie of the year honors with a fifth-place finish after a 70 for 273.
The LPGA Tour takes a week off before moving to France for the Evian Championship, designated a fifth major this year.
Pettersen was pleased to have another big tournament to look forward to so late in the season.
"A little bit unusual to have a major in September, which kind of keeps the momentum and the high a bit longer throughout the season, which I kind of like," she said.
"It gives the fall a bit more of a peak. I'm real excited to see what the course looks like, get to know the greens, get to know the course, and obviously Evian is my favorite place in Europe."
Leading final-round scores on Sunday in the LPGA Safeway Classic (USA unless noted, par-72)
268 - Suzann Pettersen (NOR) 68-63-70-67
270 - Stacy Lewis 67-70-65-68
271 - Lizette Salas 66-68-68-69
272 - Cristie Kerr 66-68-69-69
273 - Caroline Masson (GER) 69-64-70-70
274 - Gerina Piller 67-72-69-66, Sandra Gal (GER) 66-66-73-69
275 - Karrie Webb (AUS) 69-67-67-72
276 - Dewi Claire Schreefel (NED) 70-70-69-67, Lexi Thompson 65-70-71-70, Austin Ernst 67-75-62-72, Sandra Changkija 68-66-69-73, Pornanong Phatlum (THA) 64-66-71-75, Yani Tseng (TPE) 67-68-63-78
277 - Ai Miyazato (JPN) 67-70-73-67, Yoo Sun-Young (KOR) 68-70-71-68, Shin Ji-Yai (KOR) 68-68-71-70, Heather Bowie Young 67-69-71-70, Beatriz Recari (ESP) 71-66-69-71, Choi Na-Yeon (KOR) 70-66-70-71, Angela Stanford 71-67-67-72, Anna Nordqvist (SWE) 69-70-63-75
278 - Paige MacKenzie 71-68-70-69, Brittany Lang 68-68-68-74, Morgan Pressel 69-68-65-76
279 - Michelle Wie 67-73-72-67, Pernilla Lindberg (SWE) 68-74-67-70, Han Hee-Won (KOR) 71-65-72-71, Natalie Gulbis 68-68-70-73