It's no secret that great teams need just a sniff to take advantage of the slightest weakness, and Melbourne didn't relent when given the chance.

The Demons raced away to a five-goal head-start before the Saints put through their first via Rowan Marshall early in the second, with the home side's nine-goal opening half dealing enough to damage to put a win out of reach.

It was a hard lesson learned on Sunday afternoon that being just a touch behind the eight-ball was enough to be exploited, and despite braver ball movement coming after half-time to unsettle Melbourne’s level-headed defence, the Saints simply weren’t strong enough for long enough against their undefeated opposition, whose winning streak extended to 20 games.

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The experience has come at the right time with matches against Geelong, Adelaide (away), North Melbourne and Brisbane (away) to come in the next sequence of games.

“We were a bit too reactive early. They threw the first punch which gave them that head-start and we were crawling our way back ever since,” Callum Wilkie told saints.com.au post-match.

“You can’t give a quality team like Melbourne a head-start like that. We showed in that third quarter and a bit in the fourth what we can do and our ability to put them under a bit of pressure, but we just didn’t execute that in the first half which was disappointing.

“You’ve just got to be on for 100 per cent of the game and we weren’t. If you have lapses of concentration like that against a quality team like Melbourne, they’re going to make you pay.”

Melbourne registered 49 points at stoppage against St Kilda’s 13 – despite the Saints pipping their opponents for total clearances (29-30) – but it was the reigning Premiers’ effectiveness at winning them inside attacking-50 and then converting which was most damaging.

The Saints trimmed the margin after half-time to 22 points after kicking four unanswered goals either side of the main break, yet couldn’t steady the ship for extended periods as the Dees’ big names came to play.

Senior coach Brett Ratten said although his side played well in patches, it wasn't going to be enough to knock the Demons off their perch.

“I think there was periods where we showed glimpses and probably that’s the challenge for us… Melbourne are there for four quarters and you can’t just say we’re going to play a half or five minutes here and then drop off, you have to play the full game,” Ratten said.

“We did have some things in the game where we thought, ‘if we keep moving the ball this way or defending that way or our contest work was at that level, we’re in the game’.

“The difference between the two teams was one team did it for four quarters and one didn’t.

“We got a snapshot of what the best looks like.”