GRANT Birchall says Hawthorn's defenders will approach their preliminary final against Collingwood with confidence after a strong performance in the 36-point win over the Sydney Swans on Friday night.

The Hawks' back six was criticised after the week one finals loss to Geelong, but atoned in the semi-final seven days later.

Whereas the Cats managed 25 contested marks and 14 marks inside attacking 50 in a dominant aerial display, the Swans were restricted to 11 contested marks and 10 marks inside 50.

The Sydney Swans' key forwards Sam Reid and Matt Spangher had little impact on the match, as Josh Gibson compiled an AFL record 21 spoils.

Birchall said improvement in the air had been a must for the Hawks' defence.

"There was a bit of a focus going into the game last night to kill the high ball," the 23 year-old said at Waverley Park before the team's recovery session on Saturday morning.

"I thought we did that pretty consistently throughout the night last night, which was great.

"'Gibbo' in particular was outstanding.

"He's had a great season and hopefully he can continue that this Friday night."

Birchall said the key to stopping imposing Magpies duo Travis Cloke and Chris Dawes would once again be to work together.

"It's obviously going to be a big challenge, with Cloke and Dawes and those guys in good touch," he said.

"We'll have to help each other out as best we can down there.

"I'm sure that if we work as a team, that sort of thing will sort itself out."

Collingwood won the two teams' only encounter this season by 41 points in round 15, but Birchall said Hawthorn would go in with high hopes of causing an upset.

"I guess anything can happen from here on in," Birchall said.

"We'll go in confident.

"We're fresh and we're hungry, so we'll give it our best shot."