Geelong coach Mark Thompson celebrated his contract extension at Skilled Stadium by watching his all-conquering Cats chalk up win number 55 in their past 58 matches on Sunday to ensure they head into next week's top-of-the-table showdown against St Kilda still unbeaten.

The Cats wracked up win number 13 in a row to start season 2009, against an outclassed Port Adelaide, but it wasn't all smiles for Thompson.

While the Cats were never in any danger of defeat on a day when Thompson signed a two year contract extension tying him to Skilled Stadium until the end of 2011 - the Cats' coach would not have been happy with the performance of his key forwards or his team's dismal final quarter.

Despite the Cats dominating possession during their 18.14 (122) to 13.10 (88) victory, their two key forwards in Cameron Mooney and Tom Hawkins and this year's leading goalkicker Steve Johnson had little impact on the game.

In fact the trio kicked just three goals between them despite having plenty of chances thanks to the dominance of the Cats' fantastic midfield as the home side wracked up 87 more possessions for the game.

Instead it was the underrated Shannon Byrnes, who the hero after kicking four goals to go with the five he kicked in last week's win against Fremantle.

As for Port, their fifth loss in their past seven matches is not likely to have an effect on their coaching situation with Mark Williams still expected to be rewarded with a new two year deal this week.

But watching this game on Sunday, it was hard to believe these two teams played off in the 2007 grand final and indeed you could easily argue the Power has never recovered from the record 119 point mauling they received from the Cats that day.

While the Cats have gone from strength to strength - despite last year's shock grand final loss to Hawthorn - Port continues to perform like a mid-table side and only had defenders Troy Chaplin, Alipate Carlile and Toby Thurstans to thank for coming away from Skilled Stadium with at least their pride intact on Sunday.

But besides those three it was really on ex-Tiger David Rodan who tried to generate any attacking momentum for the Power although Kane Cornes at least restricted the influence of Cats' playmaker Joel Selwood but at the expense of his own game.

After two trips to Perth for their last two matches, the Cats appeared relieved to be back on home soil as they cruised to a 40 point quarter time lead.

Such was Geelong's dominance, as they slammed on seven goals to one, that the team wracked up 134 possessions to 62 and went inside their forward 50 on 19 occasions to just four for Port in the first term.

It was the Cats' pair of shaven-headed geniuses in Gary Ablett and Paul Chapman, who did the early damage with 23 first quarter possessions between them while Byrnes kicked three first quarter goals.

Port briefly threatened to get back into the game in the second term when they outscored the Cats - thanks to two goals from former Geelong player Jason Davenport - but the natural order was restored in the third term as the Cats' slammed on another six goals to one despite the continued struggles of their big forwards.

However against the AFL's best defence next week in St Kilda, the Cats will desperately need their key forwards performing far better than they did on Sunday as the Power at least fought the game out by easily outscoring the Cats in the final term as the home side's focus appeared to already on next week's blockbuster against the Saints.

GEELONG: 7.5, 10.9, 16.13, 18.14 (122)
PORT ADELAIDE: 1.1, 6.3, 7.4, 13.9 (87)

GOALS: Geelong: Byrnes 4, Ablett 2, Bartel 2, Chapman 2, Varcoe, Kelly, Corey, S Johnson, Mooney, Hawkins, Ling, Milburn
Port: Tredrea 3, Carr 2, Davenport 2, Ebert 2, Logan 2, Gray, Westhoff
BEST: Geelong: Ablett, Corey, Chapman, Scarlett, Byrnes, Milburn, Mackie, Kelly
Port: Chaplin, Carlile, Rodan, Thurstans, Cornes, Davenport
INJURIES: Geelong: D Johnson (strained calf)
Port: Nil
UMPIRES: Margetts, Rosebury, Mollison
REPORTS: Port Adelaide: P Burgoyne reported by field umpire Mollison for engaging in rough conduct against Geelong's James Kelly
CHANGES: Nil
CROWD: 21,142 at Skilled Stadium