With Blake Shinn sidelined by injury, Tim Clark picked up the plum mount on the $3.20 favourite and was able to position him three-wide with cover from his wide draw.
The four-year-old burst clear in the straight and staved off an initial surge from eventual third placegetter Private Eye ($11) and another late challenge from runner-up Yellow Brick ($41) to score.
"He travelled so well. I probably let him loose a bit early but it was his grand final, there is no tomorrow, so I wasn't going to die wondering," said Clark, who won his first Stradbroke Handicap (1400m) aboard Alligator Blood in 2022.
"He really let rip. Maybe wandered a bit late. I could feel Yellow Brick coming late and he surged again.
"I love getting up to Queensland and to win the 'Straddie' has just iced what has been a great carnival."
Ben Hayes said War Machine's lead-up to Saturday's 1400m showpiece had been smooth and the horse did everything right on race day.
He added that people expected the son of Harry's Angel to have a massive frame due to his name but said he was more athletically conformed, similar to stable flag bearer and multiple Group 1 winner Mr Brightside.
"They expect him to be a big, powerful horse but he's got a physique like Mr Brightside so hopefully he is the same," Hayes said.
