COLLINGWOOD has kept its top-four bid alive and left Port Adelaide's finals hopes hanging by a thread after a rampaging seven-goal final quarter set up an emphatic 51-point victory at the MCG on Saturday.

The Magpies led by just six points in the dying minutes of the third quarter after the teams had waged the type of hard-fought contest you'd expect of clubs looking to position themselves for successful September campaigns.

However, the game turned decisively when Steven Motlop conceded an undisciplined 50m penalty late in the third term.

PIES POWER HOME Full match coverage and stats

It sparked a run of eight unanswered Collingwood goals and, with the Power not adding another major until the dying seconds of the game, the Magpies cruised to a 17.13 (115) to 10.4 (64) victory that broke a four-game losing streak against Port.

Collingwood, who started the round fifth on the ladder less than three per cent behind fourth-placed Hawthorn, climbed to third after their win, but will likely slip back to fifth by the end of Saturday if Greater Western Sydney beats Sydney at Spotless Stadium and the Hawks defeat St Kilda at Etihad Stadium.

There had been heavy rain in the lead-up to the game, but the sun came out in time for the opening bounce and kept shining for much of the afternoon.

Magpies fans were smiling just as brightly at the end of the game as they looked forward to their first final series since 2012.

Collingwood led by one point at quarter-time and 17 points at half-time, but knowing their season was on the line the Power responded, closing to within four points after kicking the opening two goals of the third term, through Robbie Gray and Paddy Ryder.

The game then descended into a defensive scrap – it had rained briefly at the start of the third quarter – as both teams struggled to find a decisive way forward, with backwards handballs, hurried kicks and turnovers the order of the term.

The Power let the Magpies off the hook late in the quarter, however, when Motlop gave away the fateful 50m penalty after hitting Brayden Maynard in the chest.

COX'S LITTLE-MAN MOMENT Five talking points

It was not forceful enough to warrant a report, but it was enough to put Adam Oxley within scoring distance and the Magpie defender made no mistake with his set shot to give Collingwood a 12-point advantage.

Brodie Grundy (25 possessions, 41 hit-outs, eight clearances and eight tackles) was outstanding in the ruck for the Magpies, as were Taylor Adams (30 possessions – 23 in the first half – seven tackles and five clearances), Steele Sidebottom (33 possessions, five tackles and one goal) and Scott Pendlebury (25 possessions, seven tackles and five clearances) through the midfield.

Brayden Maynard (23 possessions and eight tackles) mixed stingy defence with damaging counter-attack, while Chris Mayne (27 possessions) continued his resurgence this year.

Collingwood coach Nathan Buckley was understandably pleased with his team's ability to put Port to the sword late in the match.

"We didn't think we started the game that well … our backs held up really well for the majority of the match, but early they were able to win some one-on-ones," Buckley said.

GAMEBREAKER Adams steps up as Pies trounce Port

"They found some shots on goal (and) they nailed them all, but I thought on ground, as much as off ground, in the breaks we were able to make some adjustments that just reinforced our strengths and took some of the opposition's away.

"The last 45 minutes was a really consolidated brand of football – on both sides of the ball and the contest – so that was a good example of us playing pretty solid footy."

Port's loss was its third in a row and its fifth from its past six matches.

After round 16 the Power had sat fourth on the ladder, but to make the finals they will now have to defeat Essendon at Adelaide Oval next Friday night and hope other results fall their way.

"It was really disappointing with so much to play for in that last quarter. Collingwood just kept applying the pressure and they kept turning the heat up and we were unable to go with them at any stage in the last quarter," Port coach Ken Hinkley said after the game.

"We probably hung in as best we could because we didn't look convincing at any stage. They just kept hunting us and we kept feeling their hunt.

"The scoreboard got us right by the end, I thought that was the margin between the two teams. One team was playing really strong aggressive football and one team was playing quite passive football."

Port captain Travis Boak (27 possessions, five clearances and two goals) led from the front, and received able support through the midfield from Motlop (28 possessions and five clearances) and Ollie Wines (29 possessions and four clearances).

Mobile tall Justin Westhoff (22 possessions, 10 tackles and one goal) worked hard all over the ground, while Paddy Ryder (three goals) was noticeably restricted by his hip and Achilles tendon issues but at least gave the Power a target in attack.

MEDICAL ROOM
Collingwood: Jordan De Goey spent the final 15 minutes of the game on the interchange bench icing his leg, but coach Nathan Buckley stressed post-match that this had been a purely precautionary measure.

Port Adelaide: Jack Watts came from the ground late in the first term with a left leg issue. The forward returned midway through the second quarter and played out the match. "I haven't had an update," Hinkley said of Watts' injury after the match. "He got a whack in the knee so I'm not sure how bad that will be."

NEXT UP
The Magpies play Fremantle next Saturday afternoon at Optus Stadium, in what will be their first game at the new home of West Australian football. The Power host Essendon at Adelaide Oval next Friday night, when they will try to break a two-game losing streak against the Bombers.

COLLINGWOOD          4.2       9.7       10.11   17.13 (115)
PORT ADELAIDE         4.1       7.2       9.4       10.4 (64)

GOALS
Collingwood: Stephenson 2, Phillips 2, Mihocek 2, De Goey 2, Sier, Varcoe, Adams, Oxley, Sidebottom, Cox, Grundy, Mayne, Thomas
Port Adelaide: Ryder 3, Boak 2, Westhoff, Watts, Polec, R.Gray, S.Gray

BEST 
Collingwood: Grundy, Adams, Sidebottom, Pendlebury, Mayne, Maynard
Port Adelaide: Motlop, Boak, Westhoff, Wines, Polec, R.Gray

INJURIES
Collingwood: De Goey (leg)
Port Adelaide: Watts (left knee)

Reports: Nil

Umpires: Dalgleish, Nicholls, Fleer 

Official crowd: 46,286 at the MCG

More to come.