The Saints trailed by a goal at three-quarter time but exploded in the final term, booting six goals to one.

Jack Steven (29 disposals, two goals) was dominant in the midfield, half-back Dylan Roberton continued his stellar season and young forward Blake Acres sparked the Saints' fourth-quarter run with consecutive goals.

With a crowd of 21,160 in attendance, it was the Saints' best win for the year, and one that showed they belonged on the Friday night stage after a year-long absence.

There was little separating the two sides during a fast-paced start but problems soon emerged for the Giants, with defender Adam Kennedy suffering a game-ending knee injury midway through the first quarter.

The 24-year-old appeared to be in immense discomfort after landing awkwardly during a marking contest and was on crutches in the rooms.

The Giants were soon reduced to two players on the interchange bench when Nathan Wilson's head was slammed into the turf in an aggressive Koby Stevens tackle.

The tackle was deemed fair at the time - Stevens won a holding-the-ball free kick as a result of it - but the incident is bound to be scrutinised by the match review panel.

Wilson went to the rooms for concussion tests but returned after halftime and was immediately in the thick of the action, setting up a Rory Lobb goal to extend the Giants' narrow lead.

The plucky Saints refused to go away but struggled to convert their chances, with back-to-back turnovers from Giants veteran Heath Shaw going unpunished.

St Kilda levelled the scores late in the third term before Devon Smith's 60m bomb kept the Giants ahead at the final break.

But the final term belonged to St Kilda, with Acres booting two majors in as many minutes on the back of Steven's outstanding midfield work.

Steven capped off a best-on-ground performance with his second goal to put the icing on the cake as the Saints moved in to the top eight.

It was a rough comedown for GWS after their thrilling Friday night victory over the Western Bulldogs last week.

Stephen Coniglio, Tom Scully and Callan Ward were all impressive but the Giants couldn't overcome the Saints' fanatical pressure.

Goals: St Kilda: J Gresham 3 B Acres 2 J Billings 2 J Steven 2 N Wright 2 D Minchington D Roberton J Bruce J Newnes T Membrey. GWS: J Cameron 2 T Scully 2 D Shiel D Smith J Hopper J Patton N Wilson R Lobb S Coniglio T Taranto.

Umpires: Brett Rosebury, Brendan Hosking, Andrew Stephens.