With just one round to play, fifth-placed Adelaide (36 points) can't catch Victory (41 points) after they failed to upset ladder-leaders Sydney FC in the late Sunday night game.

Melbourne looked as if they would come away empty-handed against the last-placed Phoenix before their two late goals, with Athiu in the thick of the action after he replaced star Besart Berisha in the 72nd minute.

In only his fourth A-League match the 25-year-old Sudanese-born striker, who is on loan from National Premier League club Heidelberg United, was brought down in the box by Wellington's Dylan Fox.

Dutchman Leroy George stepped up to slot the equalising penalty goal.

Four minutes later, Athiu dived for a header into the back of the net after a beautiful ball from James Troisi to seal the win for the home side.

Phoenix's goal came in the first half off a Victory own goal, scored by veteran Leigh Broxham, when the left back - while on the ground - threw a foot out to try to clear the ball only for it to land in the net.

Victory coach Kevin Muscat said his team showed heart in their display.

"It didn't go our way early on to go one goal down ... for long periods we weren't at our sharpest but that was because of the expectation on us and to finish as we did showed an enormous amount of heart," Muscat said.

"That result came from somewhere really deep."

Returning from their midweek Asian Champions League loss in South Korea, Melbourne looked flat in the opening half while Phoenix appeared hungry to avoid the wooden spoon.

Victory fired up the tempo in the second half, bringing on skipper Carl Valeri and George, but they continued to waste their chances until the late flourish.

Muscat said Athiu, who was working in a furniture store before joining Victory, offered the team something different with his height and athleticism which would be hugely valuable heading into the finals.

Dubbed "King" Kenny in the NPL, he scored his first goal for the A-League club in their ACL loss to Ulsan Hyundai.

"He's offering something and it's education for him," Muscat said.

"Kenny has got a lot of scope to improve."

Australian Associated Press