St Kilda’s AFL finals hopes are still alive after a 25-point win over Melbourne at the MCG but a knee injury to captain Nick Riewoldt threatens his availability.

Just 15 minutes into Saturday’s game, Riewoldt hyper-extended his right knee while attempting to complete a mark and was taken off on a stretcher.

Riewoldt had looked in menacing form early, having already had four possessions and kicking a goal, and the Saints went on to win 16.11 (107) to 12.10 (82).

The skipper was taken to hospital for scans during the third term and cleared of any structural damage to the knee that has caused him problems in recent years.

However, there could still be tendon damage in the area and he is set to have more scans this week.

The Saints had a 23-point lead at the first change and the Demons managed to reduce that to 16 by halftime after getting some control of the midfield and providing opportunities for their forwards.

Goals came from Jeremy Howe and Sam Blease as Melbourne gained control and St Kilda could find no avenue to goal.

The Demons kicked the opening two majors of the third quarter and, when Blease ran into an unguarded goal at the five-minute mark of the term, the Saints were clinging to a four-point lead.

But rather than panic, the Saints steadied and Beau Wilkes, who ended the day with five goals, stood up as the marking forward so desperately needed in Riewoldt’s absence.

The Saints kicked the last seven goals in the term to break the back of the contest and lead by a commanding 50 points by the final change.