There are two ways to view an AFL semi-final, one where the winner lives to fight another day and the loser goes home.

Viewed in its entirety, Saturday's Western Bulldogs-Sydney semi-final was a cracking game - not the most brilliant standard - but the comeback by the Bulldogs to win by five points was as exciting a finals match as you could wish to see.

But as a pointer to next week, it is doubtful that Ross Lyon and the St Kilda coaching staff would have been shaking in their boots as they left the MCG. The Dogs showed some ticker, but would appear to be a level below what we've seen from the Saints of late.

More of that later. The tale of this match will be told in the last two and a half minutes of the second quarter, when the Dogs kicked two quick goals to reduce the margin from a mountain-like five goals, to a crest-like three.

It was the sort of window the Bulldogs needed to give themselves a chance.

They had Barry Hall as their lone hope up forward and he didn't let his team down, but the move of Robert Murphy as the lead-up, second option forward also worked a treat once Rodney Eade made the move in the second term.

Also helping the Dogs was getting on top in the centre. They won the clearances handily after half-time, with Sydney ruckman Shane Mumford injuring his good leg and therefore robbed of most of his mobility. Matthew Boyd played an enormous final term, Jarrod Harbrow provided great drive off half-back and Daniel Giansiracusa - in the gun for much of the week coming off a poor outing against Collingwood - kicked important goals.

It was enough to get the Dogs in front and while the Swans kept pressing, it was the Bulldogs who got home and the Swans who go home. Brad Johnson gets another match, while Paul Roos and Brett Kirk do not.

So on to next week. The win by the Bulldogs gives us the same preliminary finals match-ups as last season. We have discussed - and will further the Cats and the Pies - but it just feels right to have the Saints and the Dogs matching up again for a berth in the grand final.

The Dogs feel they were jibbed this time last year - a couple of soft frees to Nick Riewoldt ended up making a world of difference. They beat the Saints in the NAB Cup Grand Final then conceded three goals in the last five minutes to lose to the Saints in round six - their only meeting in the home and away season.

They're itching to get another crack at the Saints, but they're going to have to lift significantly. Giansiracusa and a few of his fellow forwards need to play four quarters, not two because the Dogs won't get all that many chances to hurt the Saints on the scoreboard, so they'll need to make the most of every opportunity they get.

And the Dogs will sweat over the fitness of key defenders Brian Lake and Tom Williams. Both looked tired and sore against the Swans, so heaven help them if they're less than cherry ripe against Riewoldt next weekend - he'll take them to the cleaners.