The 26-year-old blazed scores of 64-64-63 and 69 to finish six shots clear of his nearest rival Clint Rice (-14).
Former New Zealand under-19 cricketer Michael Hendry capped a strong week with a closing 68 to finish in third spot at -13.
Tasmanian Rice produced the round of the day yesterday with a 6-under-par 64 but not even his valiant late dash could deny Bowditch one of his major career wins.
Bowditch’s victory followed his disappointing finish to the recent USA Nationwide Tour and provides him with a perfect springboard into this week’s Australian Masters at Kingston Heath where he will tee up with world golf phenomenon Tiger Woods.
The affable Bowditch admitted to having a few anxious moments yesterday after Rice raced to 5-under par after five holes but the Queenslander’s putting held firm when it was put to the test.
“The course played a little tougher today and I was thankful to go into today eight shots in front,” Bowditch said.
“My putting today was probably the best it’s been all week.
“I holed some nice putts when I needed them to help me out of a bit of trouble.”
Bowditch set himself a prophetic pre-tournament goal of shooting 20-under par around the tight City layout.
“Around 20 to 25 under was my target and it was nice to be able to come here and shoot that,” Bowditch said.
“I drove the ball really well all week and although the fairways are narrow and a little short you can get rewards here for playing attacking golf.
“I just hope I can hold that form now heading to Melbourne next week.
“I’m looking forward to playing the Masters on what is my favourite golf course in Australia.
“Hopefully from there I’ll head back to the States and try to get my job back.
“But I enjoyed my week here on a golf course presented in terrific order.
“I had a great time. The people are fantastic and they treat you great.”
Rice was delighted with his last-day charge which ate into Bowditch’s overnight 8-shot lead.
But he summed up the feeling of his fellow players during his runner-up acceptance speech.
“Realistically we were playing for second out there today,” Rice said.
“Steven was more or less in cruise control today.”
Brisbane’s Adam Boyer finished the tournament’s leading amateur at even par after rounds of 66-72-71-71.
260: Steve Bowditch (64, 64, 63, 69) $16,500
266: Clint Rice (67, 69, 66, 64) $10,450
267: Michael Hendry (70, 65, 64, 68) $7700
269: Michael Wright (68, 68, 67, 66)
270: Brad McIntosh (71, 61, 68, 70)
271: Steve Collins (64, 68, 69, 70); Adam Blyth (69, 64, 66, 72)
272: Marcus Cain (68, 69, 67, 68); Jason Norris (67, 66, 68, 71); Eddie Barr (64, 69, 66, 73)
275: Richard Backwell (69, 66, 67, 73)
288: Paul Habgood (69, 71, 73, 75)
Update your news preferences and get the latest news delivered to your inbox.