Leigh Matthews has a theory that a football team looks a whole lot better when their top six fires. Any doubters should watch Sydney play more.

At a time when several leading fancies have stumbled, the Swans are trampling over their rivals. This week it was St Kilda's turn to be put to the sword, their game bid for a finals berth extinguished after the Swans' crushing 70-point win on Saturday night.

This loomed as a danger game for the Swans, who were facing an in-form team at a venue where they have proven hard to beat. And the events of the first half had done little to dispel those thoughts.

Half an hour later, however, the only danger was the game turning into a blowout after the Swans destroyed the Saints with a blistering third term where they outscored their rival eight goals to two.

This was a performance full of authority by the Swans, who fielded nine players with fewer than 40 games' experience. Their stars all fired, none more so than Lance Franklin.

The superstar forward turned in one of his finest games of the season, booting six goals in a Swans forward line that has clicked in recent weeks. There should, in theory anyway, be more improvement to come next week when Kurt Tippett makes his expected return.

The win was set up by the old firm of Josh Kennedy, Luke Parker and Dan Hannebery, all seasoned campaigners capable of running a full four quarters. All three had 30-plus possessions and when this happens the Swans seldom lose.

It was a dirty and bruising night for the Saints, who were given a football lesson by a side that works just as hard when they don't have the ball. They also lost Tom Hickey and Sam Fisher to injury though their departures came when the game was already over.

There were some positives. They had played Sydney twice under Alan Richardson before this and on both occasions they were out of the game by the first break. This time they served it right up to their more fancied opponent in the first half.

Knowing an arm-wrestle would better suit the Swans, the Saints would have liked the frenetic tempo in which the game started. Their pace was troubling the Swans, who, uncharacteristically, laid just three tackles in the opening 13 minutes.

This would have been a concern for John Longmire as pressure is one of his team's trademarks. Another is their ability to win the contested ball, which was also down in the first term but lifted in the second.

Twice the Swans challenged and on both occasions the Saints responded, though the game was now starting to be played on red and white terms. Parker, Kennedy and Hannebery were making their mark in the middle while Lance Franklin was looking dangerous.

Suddenly, runs like the one Jack Steven made in the first term were non-existent. The Saints were doing well to hold on but a rubber band can only stretch so far before it snaps.

Breaking point came shortly after half-time as the effort of the previous term's chasing began taking its toll. The Swans flexed their muscle and the Saints were unable to find another gear.

They had reason to be unhappy with the umpires, who missed high contact on two occasions which led to goals, though it was by no means the reason their game was unravelling.

Their ball movement, fluid in the first half, was now stilted. When they did get through the Swans press and push forward of centre they could not beat the likes Dane Rampe and the much-improved Aliir Aliir, who is fast becoming a cult figure among the red and white faithful.