TOKYO, November 10, 2013 (AFP) - Lu finished with a total of 14-under 202 to win by two shots from South Korea's Chella Choi, who closed with a 66 at the Kintetsu Kashikojima Country Club in central Japan.
World number three Stacy Lewis, the defending champion, could only finish eighth in the LPGA-sanctioned event after a bogey on the par-five 18th gave her a final-round 70.
World number one Inbee Park of South Korea and Norway's Suzann Pettersen, ranked second, did not compete.
"I've been waiting for this day for so long," said Lu, who earned $180,000 for her victory. "This is my first win, it's been eight years on tour. I'm really happy. Really nervous and really happy."
Lu and Choi began the day two shots off the pace set by the Japanese trio Mamiko Higa, Yuki Ichinose and Shiho Oyama, but Choi moved to the top of the leaderboard with her fifth birdie on the par-four ninth.
Lu made the turn still tied for second, but then rattled off four consecutive birdies from the 11th to charge into pole position as the pressure appeared to get to Choi.
The Korean settled her nerves to birdie the 16th -- her only birdie on the inward nine -- and draw level, but Lu pulled ahead again after draining a birdie putt on 17.
A 30-foot putt from Choi lipped out on the 18th and Lu finished with a flourish, sinking a 12-footer on the final hole.
"I didn't want to end up in a playoff so I knew I had to make birdies," said Lu, whose previous best finish on the LPGA Tour was a tie for second at the 2007 NW Arkansas Championship.
"At the beginning of the year I was in two playoffs and lost both. I was focusing on making birdies. Today I just tried to be calm and I was calm, except for on 18."
Lu relinquished her LPGA Tour card in 2010 and moved to Japan to play full-time on the JLPGA circuit and boasts 13 top-10 finishes this year, three of those as runner-up.
Asked if she could be lured back to the LPGA Tour next season, Lu said: "Probably, probably. It's big!"
Higa and Ichinose both carded rounds of 70 to finish tied for third. Oyama and Yumiko Yoshida tied for fifth place.
Leading scores at the $1.2 million Mizuno Classic at par-72 Kintetsu Kashikojima Country Club in central Japan after Sunday's final round:
202 - Teresa Lu (TPE) 70-68-64
204 - Chella Choi (KOR) 69-69-66
206 - Mamiko Higa (JPN) 70-66-70, Yuki Ichinose (JPN) 70-66-70
207 - Yumiko Yoshida (JPN) 74-65-68, Shiho Oyama (JPN) 68-68-71
208 - Asako Fujimoto (JPN) 70-67-71
209 - Feng Shanshan (CHN) 72-71-66, Stacy Lewis (USA) 71-68-70, Jang Eun-Bi (KOR) 69-69-71
210 - Kaori Nakamura (JPN) 69-73-68, Jiyai Shin (KOR) 69-72-69
211 - Esther Lee (KOR) 70-72-69, Catriona Matthew (GBR) 71-71-69, Harukyo Nomura (JPN) 72-69-70, Hwang Ah-Reum (KOR) 71-68-72
212 - Erina Hara (JPN) 71-73-68, Mayu Hattori (JPN) 76-68-68, Jenny Shin (KOR) 72-71-69, Sakura Yokomine (JPN) 72-71-69, Mina Harigae (JPN) 73-69-70, Han Hee-Won (KOR) 69-71-72, Brittany Lang (USA) 70-70-72, Julieta Granada (PAR) 71-68-73, Miki Saiki (JPN) 73-66-73, Junko Omote (JPN) 69-69-74