Romsey star Cameron Dawson was concussed in the opening play of the match and did not return to the field as Sunbury Kangaroos broke the game open 15.8 (98) to 8.16 (64) after a low-scoring first quarter.

Up by just one point, 1.1 to 0.6 at quarter-time, a run of Sunbury goals midway through the second quarter was given a boost when Gary Moorcroft was carded and sent from the field for 15 minutes.

Without two of its main stars the Redbacks suffered as Sunbury piled on six goals, heading to the long break 12 points in front.

Sunbury Kangaroos then took the game away in the third term, five goals to one before exchanging three goals each in the last quarter.

Chris Meacham and Matt Leonard finished with three goals each for Sunbury Kangaroos, while Mitch Streiff and Ryan Hatty were best.

Jake Bray and Stephen Burlak were Romsey's better players, along with two-goal Luke Carroll.

Sunbury had injury concerns of its own, Adam Fenton out of the action with a hamstring injury just minutes into the first quarter.

"I thought we were spectating a bit, a little bit reactive," Sunbury Kangaroos coach Dean Helmers said.

"We put pressure on Romsey in the first quarter to miss their shots. I said at quarter-time to the guys this is our chance to go on the front foot and win the game. We started leading them to the ball, running and spreading the field."

Helmers had originally planned to tag Romsey ball-winner Dean Smith-Whiting with Leigh McInerny, but when a Romsey tag came to McInerny, the Kangaroos coach told his players to back themselves.

"We focused on what we were doing. After we lost Fenton I threw some on-ball support into the forward line to provide some spark and we got that from Darragh McGovern and Ryan Hatty."

Sunbury now comes up against Riddell for a spot in the grand final, having been well off the pace in both meetings between the sides in the home and away season.

"We deliberately rested players last time and we'll find out if we're full of it or not this weekend," Helmers said.

"We went to a plan, finished third and won the first final."