Things looked grim for Geelong for about six minutes on Saturday night - until Gary Ablett took over.

The champion's preliminary-final performance against Collingwood at the MCG showed why he is the Brownlow Medal favourite and his peers have voted him the AFL's best player for a third straight season.

Just as St Kilda captain Nick Riewoldt proved his class by willing his team home against the Western Bulldogs on Friday night, Ablett turned the tide a night later.

Riewoldt will carry much of the St Kilda's hopes in next Saturday's grand final.

But another blond Saint, Clint Jones, will be almost as important. He's likely to be handed the job on Ablett.

The Magpies had stunned Geelong in the opening six minutes, with 2.2 before the Cats looked like scoring.

Then Ablett, who started in a forward pocket, moved into the centre.

While others had started nervously, Ablett showed clean hands and quick feet to repeatedly win the ball.

He had 12 touches for the term and, after he moved into the middle, the Magpies did not score for the quarter, while Geelong piled on 3.6.

By five minutes into the second term, the Cats were 20 points up and in control.

The Magpies briefly rallied late in the half, but three Geelong goals in the first 10 minutes of the second quarter buried their hopes.

Ablett was again in the thick of it, combining with Cameron Ling to control the midfield, but he preferred to pay tribute to the entire team's work ethic after the Cats marched into a third successive grand final.

"I just thought everyone did their bit," Ablett said.

"It was one of those days that 22 players played a role for the team. You can't afford to have six or eight players down in a preliminary final.

"We've got to make sure we take that to next week."

Other good signs for the Cats included ruckman Brad Ottens' continued improvement after a long injury absence and forward Steve Johnson's ominous signs of class after more than a month out.

Both missed the six-point loss to the Saints in their epic round-14 clash.

Ling ensured Collingwood's Brownlow fancy, Dane Swan, was kept below his usual prolific output.

But other big-name Magpies were much quieter, notably forwards Travis Cloke and Leon Davis, the latter earning Bronx cheers late in the game.

Meanwhile, Ablett soaked up the applause for a late running goal.

A year ago, his distress was obvious after he played his heart out with 34 disposals and two goals in the shock grand-final loss to Hawthorn.

He picked up another 34 disposals and two goals against the Magpies on Saturday night and looks primed for something special next Saturday.