Munro (63) won the final at the Westpac Bowls Stadium with 31 points, ahead of John Cross (Fairfield) 25 and Russell Dawe (Port Chalmers) 23, in the quick-fire game that has a one-hour, 15-minute time limit.
The first two placegetters will receive an all-expenses paid trip to the national final at Hamilton in September.
Munro has been playing bowls for 13 years and has won one Bowls Dunedin centre title.
This is his fourth year in the PBA and the first time he has won a major event that takes him to a national final.
"I'm rapt," Munro said. "That is why you come down to the stadium to play. You want results."
The Shanghai tournament is a quick-fire, shorter version of the game, invented by Dunedin's Ken Walker, who hopes it will arrest the rapid decline in registered bowlers by creating a fun version of bowls.
Three players are on the mat together in a singles match and six points are available on each end. The closest bowl gets three points, the second bowl two and the third-closest bowl one point. The first player to 31 points wins the game.
Munro had two significant ends that won him the game.
He took the joker on the fourth end, doubled his score, and shot out to 13 points, and was followed by Dawe on 9 and Cross 5.
The other significant end was the 10th when he scored all the points for a Shanghai and doubled his score on the end.
The six points took him to 28, and he was followed by Cross on 18 and Dawe 17.
"I just stuck to the draw," Munro said. "I relied on it and only played two upshots in the final."
Dawe also finished third last year.
The significant end of the day came in the semifinal when Dawe took the joker and then had all the shots for a Shanghai that gave him 12 points on the end.
He won the semifinal with 31 and was ahead of Ivan Webber (Leith) 22 and Bill Hinton (Andersons Bay) 13.
Munro won the other semifinal with 31 points, from Cross 29 and Russell Jones (Southland) 16.
Joko Susilo (Andersons Bay) won the plate final with 24 points, from Andy McLean (North East Valley) 22 and Maree Jones (Southland) 19.
A capacity field of 48 bowlers participated.
