AN INSPIRED St Kilda is on top of the AFL ladder for the first time since 2010, belting a listless Melbourne by 40 points in their twilight clash at the MCG on Saturday.

The Saints broke an early deadlock to pile on eight successive goals while keeping the Demons goalless for the best part of two quarters through the middle part of the game as they claimed their biggest scalp of the season, winning 15.5 (95) to 7.13 (55).

Rubbing salt into the wounds for the battling Melbourne was that the unlikely hero for the winners was Demon-turned-Saint Dean Kent, who, in his first game against his old club, kicked three goals and had a hand in several others with his powerful left foot.

Tim Membrey (four goals) was a constant threat in attack, while Josh Bruce (two) was also dangerous at times, and they were superbly served by the Saints' bevy of busy runners, led by Jack Billings, Jade Gresham, Seb Ross and Jack Sinclair.

Alan Richardson's team, which stumbled badly last year, has defied the critics to charge to an impressive 4-1 opening for the first time in nine years and continues to impress with its hardness around the ball, its purposeful ball use, strong defensive mechanisms and hard-working offensive game.

Meanwhile, Simon Goodwin's Demons have just as unexpectedly lurched to 1-4 for the first time in five years and are at the crossroads. They didn't win enough of the ball in the clinches, over-used the ball, butchered it by foot and didn't seem to work hard enough in defence as St Kilda created multiple loose men forward of centre on far too many occasions.

The Dees, who lost their opening three games, had hoped to continue to build on the momentum they gained from their win over Sydney at the SCG, and they started well in unseasonably warm weather when back-up ruckman Braydon Preuss kicked a goal in the opening minute.

Preuss scored two of the Demons' three goals in the first term, the second being a beauty on the run from outside the arc to drag the Dees back within four points before quarter-time.

Christian Petracca fluffed a chance to regain the lead for Melbourne in the opening minute of the second term but inexplicably missed the lot with a regulation shot from 30 metres, but he made amends three minutes later from a similar position after a clever pass from Angus Brayshaw.

A concern for the handball-happy Demons from the outset was the space they afforded the Saints when they went forward and eventually they were made to pay.

St Kilda trailed by three points midway through the second term before winning seven consecutive clearances and rattling on three consecutive goals in six minutes to lead by 15 points by half-time. This was despite the fact they trailed considerably in the inside 50 count (27-17), which told a tale of the relative efficiency of both teams.

Billings could have stretched that advantage but his late shot from 40 metres sailed out on the full – a rare blemish for the young star.

The Saints obliterated the Demons in the third term, winning the ball at will and reducing their opponents to a rabble, adding 5.3 to just three behinds.

They led by 45 points at three-quarter time and although Melbourne forward Jake Melksham kicked two goals early in the last quarter as the Dees reduced the margin to five goals with six minutes remaining, the Saints steadied late with Membrey adding his fourth major.

From four minutes into the second quarter until two minutes into the last quarter, the Demons scored just four behinds, while conceding 8.4.

St Kilda stopper Jack Steele performed a solid job on Melbourne ball-magnet Clayton Oliver, particularly in the first half, while Shane Savage controlled the tempo in the back half and star midfielder Jack Steven was rusty in his first game in three weeks but improved as the game wore on.

For Melbourne, co-captain Jack Viney was in everything early, and Oliver and Brayshaw were also workmanlike in the middle, while Christian Salem was prolific across half-back without being as damaging as usual.

Among the lowlights for the Demons were the below-par performances of key Tom McDonald and Jordan Lewis, the latter in his first game of the season after overcoming a hamstring injury.

Also of concern, Melbourne defender Neville Jetta started the game with strapping on his left knee and he continued to have issues.

It was easily the Saints' biggest win this season, eclipsing their 11-point victory over Essendon in round two, and it was the second successive time they had overcome Melbourne at the MCG, having enjoyed a rare high point in round 15 last year when they caused a two-point boilover.

Melbourne: On several occasions, Neville Jetta appeared to aggravate an existing problem with his left knee but he toughed it out to play out the game in an under-siege defence.

St Kilda: Ben Long copped a knock to his left thigh in the second quarter and later returned with strapping but showed little sign of discomfort in the third term when he nailed a shot from the arc on the run.

The Demons have just four days to lick their wounds before facing Richmond at the MCG in their Anzac Day Eve clash on Wednesday night, while the Saints have a golden opportunity to consolidate their position in the upper echelon when they host a struggling Adelaide at Marvel Stadium on Saturday night.

MELBOURNE    3.3     4.5      4.8    7.13 (55)
ST KILDA         4.1     7.2     12.5   15.5 (95)

Melbourne: Preuss 2, Melksham 2, Petracca, Brayshaw, Harmes
St Kilda: Membrey 4, Kent 3, Bruce 2, Billings 2, Acres, Lonie, Long, Parker

Melbourne: Brayshaw, Oliver, Gawn, Harmes, Salem
St Kilda: 
Billings, Kent, Membrey, Newnes, Acres, Steele, Geary

Melbourne: Nil
St Kilda: Long (corked thigh)

Reports: Nil

Umpires: Chamberlain, Whetton, Harris

Official crowd: 35,558 at the MCG