ST KILDA coach Alan Richardson has slammed his team's lack of physicality against a "tougher" Sydney outfit, saying the Saints' effort in a disastrous opening to Saturday night's game was "unacceptable".

The Saints allowed Sydney to slam on the first nine goals at Etihad Stadium before a late Josh Battle goal cut the quarter-time margin to 48 points.

The Swans' 9.1 return was their biggest in an opening quarter against St Kilda, while they dominated the clearances 18-6 and uncontested possessions 69-42 in an explosive term that set up a 71-point victory.

SWANS SMASH SAINTS Full match coverage and stats

Richardson did not mince words after the game when asked to explain his team's first quarter.

"(We were) smashed, just beaten comprehensively everywhere by an outstanding footy team," Richardson said.

"We just weren't in the fight, weren't in the game. We came in with a young defence, it was good to have 'Browny' (Nathan Brown) there. Whenever they went forward they looked cleaner, certainly tougher, they were a ruthless footy team, and we were far from that.

SWANS' STREAK CONTINUES Five talking points

"We let ourselves down badly today, there's no doubt about that. It was an unacceptable performance, it was unacceptable in terms of the physical commitment required to play AFL footy full stop, but particularly against a side like Sydney.

"Full credit to them, they were super impressive. (But) we can't put up with that performance early when the game is up for grabs."

The Saints' loss was their biggest since round 11, 2016, and continued a dreadful start to the season.

WATCH Alan Richardson's full post-match media conference

Widely tipped to return to the finals this year for the first time since 2011, St Kilda has just one win and a draw to its credit after 12 rounds – its worst opening to a season since 2000.

Richardson, who was re-signed until the end of 2020 in October last year, was coaching St Kilda for the 100th time on Saturday night, his tenure having netted just 34 wins.

The fifth-year coach conceded the Saints had taken a significant step backwards after encouraging performances against Richmond and West Coast the previous two rounds, but was adamant he had not lost confidence in his ability as a coach or in his team.

SHOWREEL Swans' first term blitz

"When you have a performance like that, of course you ask questions of each other. The coaches ask questions of each other, I've asked and challenged the playing group in that space," he said.

"We're in this together. Collectively – and I include myself in this – we'll be really critical of the way that we started and critical of the fact that physically we weren't at the level.

"We'll look at everything."

Despite being beaten so comprehensively by the Swans, Richardson was confident his team could bounce back against Gold Coast at Metricon Stadium next Saturday.

"Our focus is to make sure the players have real clarity on what is the gap between our expectation and what we're able to deliver," he said.

"It's going to be pretty easy this week for them to be able to walk out of reviews, walk out of that meeting we just had and understand what needs to be done.

"That's the main thing that we need to get across."