After a quiet first three quarters against the Western Bulldogs on Saturday night, Brennan burst into life with 11 possessions, four marks and four clearances in term four – helping lift the Lions to an 11-point come-from-behind victory.
The performance was reminiscent of his influential 12-disposal final stanza in the round 12 win over Adelaide and also a three-goal last term in a losing effort against Essendon a month ago.
"At three-quarter time I was really frustrated – I'd been floating from the forward pocket to half-forward and through the midfield, struggling with the rotations and battling to get the ball," Brennan said.
"Leigh (Matthews) chucked me into the middle straight away to start the last quarter and I knew I had to do something.
"I was probably running around a bit silly for the first five minutes but I knew if I kept running I'd eventually get the ball in my hands.
"I was in the right place at the right time luckily. It was good to get a few touches and great to get over the line."
Saturday night's result could prove pivotal to the Lions' finals chances, as it lifted them back inside the top eight on percentage, with the previously eighth-placed St Kilda still to play Fremantle on Sunday evening.
Brennan said the win reflected not only an improvement in the Lions' ability to hold their nerve in a tight game but also a significantly better tackling effort than the week before against Hawthorn.
"I haven't looked at our tackling numbers yet – we probably missed a couple but I think you'd have to say it was a pretty fierce tackling effort and just about where it needs to be," Brennan said.
"We missed 23 tackles in the second half against Hawthorn. We aim to miss 20 or less for the game, so if we miss more than 20 in one half we know we're not going to win.
"If you miss tackles against the Bulldogs they are a forward-running team and they'll just boot it or handball if forward and be gone.
"So it was a much better effort there."
Brennan said the Gabba crowd reached close to season-best noise levels against the Dogs and former Lion Jason Akermanis and he's hopeful that will continue for the Lions' next crunch assignment against Carlton on Saturday night.
The Blues also remain in the finals hunt but the 24-year-old is looking to dent their September aspirations, along with those of his Carlton-supporting brother Aaron.
"When we got the last two goals the crowd was really pumping and it was like the Lions of old," Brennan said.
"What we want is for the Gabba to be a fortress and for other teams to feel the crowd on their back.
