Carlton players may have felt the weight of the nation upon them when the Blues theme song briefly became the Australian national anthem before the AFL semi-final against West Coast.

The correct tune was quickly played and most had a chuckle although, in the west, the error probably served to reinforce the 'us versus them' mentality when one of WA's AFL teams face a Victorian rival.

Whatever the battlecry, it was clearly war as the two teams charged into the Battle of Subiaco and there were plenty of casualties on both sides early.

Carlton's Bret Thornton was the biggest casualty of the night after landing on his neck in a marking contest in the final seconds of the first half.

Thornton spent several minutes lying on the ground as Auskick players ran out at halftime, before the Blues forward got to his feet and was assisted off the ground.

The Blues activated substitute Zach Tuohy for the start of the second half and Thornton was later taken to hospital for observation.

It wasn't the first time this season Thornton visited a Perth hospital - he spent time there after the round-21 victory over Fremantle, where he ended up with a golf ball-sized lump under his eye.

Carlton defender Heath Scotland came off second-best in the first term after being collected by Jack Darling and it was feared broken ribs were the issue as he came from the ground.

But a few minutes later, he was back and running and it was West Coast's turn to take a hit, when key forward Josh Kennedy clashed heads with Lachie Henderson.

He was out of action for much of the opening term and Eagles substitute Pat McGinnity warmed up but Kennedy refused to give in to doctors and he also returned late in the opening quarter.

As with any fighter, it's about how you get back up and Kennedy, despite one eye appearing to be partly closed, returned to kick three goals.

The first of these was a remarkable bomb from 70m that appeared headed for the boundary before it broke back towards the goals and somehow avoided Dennis Armfield and Chris Masten.

The little general Daniel Kerr became a big influence as he helped drag West Coast back into the contest during the second term.

The premiership player and runner-up in the 2005 Brownlow Medal has been dogged with injury this year and has missed big chunks of football in the latter part of the season.

But he lifted to be one of his side's leading ball-winners and demonstrated his class and poise in the second quarter, as the Eagles stormed the fort with eight goals to three.

His ability to read the play at stoppages is uncanny and this led to several centre clearances to set up scoring opportunities for the Eagles.

As in any war, there were heroes on both sides but, in the end, the Eagles planted their flag and began the long march to the MCG to face Geelong.

Brought to you by AAP © 2024 AAP