GREATER Western Sydney failed to learn the harsh lessons of its loss to Sydney last week as it was again overrun in a crushing five-point defeat to Brisbane, according to coach Adam Kingsley.

The Giants led by as much as 31 points early in the final term before the Lions surged home with the last six goals of the game to snatch the win and a spot in a preliminary final on Saturday night. 

GIANTS v LIONS Full match coverage and stats

The Swans had overcome a similar deficit in a qualifying final against their crosstown rivals, as they booted three goals in the dying stages to send the Giants into their cut-throat semi-final against the Lions at Engie Stadium.

"The final quarter was the same as really the Swans game. We didn't cope with the contest as well as what we would have liked," Kingsley said. 

"(The Lions) capitalised on their opportunities, we didn't really challenge them the other way. We certainly addressed it, we just didn't execute it. 

"That'll be one of the things that we need to work on across the summer in preparation for next season, is how to address those moments, how to deal with them better."

The Giants had earlier opened up a 44-point lead halfway through the third term before the Lions booted five goals in nine minutes to breathe life into the contest. 

Jesse Hogan helped the Giants steady that time with a pair of contested marks in the forward 50 as the spearhead dished off the first for a major to Xavier O'Halloran then booted a goal himself. 

Toby Greene then snapped the first goal of the final term to extend the Giants' lead but the hosts had few answers when the Lions came again.

"We thought we'd learned our lessons from last week against the Swans," Kingsley said. 

"Well, tonight, it was the same story, unfortunately. It would appear we haven't yet learnt that lesson, to still be proactive, to execute the system as best as we can, to remain aggressive, to be aware of the opposition when they do roll the dice a little bit.

"We're not the finished product yet. I've been saying that all year."

GWS finished in the top four for the first time since 2017 after winning seven matches in a row before losing in round 24 to the Western Bulldogs then suffering a pair of heartbreaking finals defeats.

The two defeats by a combined 11 points mean the Giants have been bundled out of the finals in straight sets for the first time.

But Kingsley is confident his side can challenge again especially after beating Brisbane twice, as well as preliminary finalists Geelong and Port Adelaide once each during the home and away season.

"To us it's clear that when we play a Giants brand of footy, it can compete with and beat any team in the competition," Kingsley said.

"We need to do it for longer, we know that. But we can't expect to win four quarters either, so we've got to be able to deal with opposition momentum a little better.

"We've seen great growth with our playing group. I think we've increased our versatility throughout the year. We've been able to introduce new players into new positions and grow them."

The Giants are hopeful that Stephen Coniglio has avoided serious injury after the midfielder came off second best in a collision with Harris Andrews on the brink of the first change and was subbed out with a cheekbone issue.