West Coast coach John Worsfold had no idea what his unlikely match-winner Eric Mackenzie was doing in the forward line in the dying minutes of Sunday's thrilling four-point win over St Kilda.

But he certainly wasn't complaining.

After kicking just one goal in his previous 87 matches, Mackenzie tripled his career goal tally at Etihad Stadium.

It was the fullback's second goal of the match - made easier when direct opponent Beau Maister slipped over at the worst possible moment - that sealed a 12.12 (84) to 11.14 (80) victory which allowed the Eagles to climb back into the top eight.

"I don't dream about Eric Mackenzie kicking many goals, I'll admit that," said Worsfold.

"Do you want the real answer (as to what he was doing deep in the forward line)?

"No idea mate.

"I don't know if he'd just come off the bench.

"There were obviously messages going out to players at that stage about what we needed to do if there was a behind scored, if there was a goal scored.

"Eric would have known what we were trying to do in terms of the next kick-in, he's obviously just read it well."

If Mackenzie was the hero, then Maister and Leigh Montagna were the villains for the luckless Saints, even if coach Scott Watters was determined not to apportion blame to any individual players.

Montagna had the chance to put the Saints seven points up late in the final term, but missed with his shot from 20 metres out when the better option would have been to handball over the top to either Stephen Milne or Nick Riewoldt, both of whom were free in the goalsquare.

Maister then spurned another chance for St Kilda and it proved extremely costly.

Shannon Hurn's long kick-in fell to Matt Rosa, who hacked the ball forward in the direction of Mackenzie.

And he did the rest.

The Saints led for the vast majority of the encounter, but were never able to get more than 18 points ahead - a point not lost on Watters.

"I thought we controlled the game for much of the night, particularly the second quarter," he said.

"But again the scoreboard doesn't lie.

"You have to take your opportunities and execute when you're in control of the game.

"It certainly wasn't for want of effort."

Milne kicked a game-high five goals for St Kilda, who remain in 16th spot on the ladder with a sorry 2-9 win-loss record.

Jack Darling booted three goals for the Eagles.

Both teams have the bye next week.