Gallen announced himself as a genuine heavyweight boxing threat after stopping former world champion Browne in the opening round at Wollongong’s Entertainment Centre, leading to a savage reaction from observers.
"He hit me with a great shot, you can't fault that from his end and he just swarmed, I didn't have the equilibrium and he capitalised," Browne said.
"[This is] definitely not the last fight [for me], it's been a year-and-a-half since my last fight, I want to stay as active as I can, whether it be someone like a Solomon Haumono, but I do want in the next couple of months to have another fight."
Gallen questioned Browne's training, or lack thereof, prior to the bout, but the 42-year-old said he had trained professionally.
"I did, honestly," Browne said.
"He was talking about me leaving it too late, I did all my fitness and work in Perth first, before I came here [to NSW].
"But the future will hold a lot of fitness in Perth, but I'll come over here three or four weeks out from the fight rather than two just to make sure everything sits in and the game plan is where it should be."
For former NRL star Gallen, this is one of the biggest upsets in Australian boxing history.
He dropped Browne with three savage right hands.
Browne beat the count, but Gallen followed up with a heavy combination of blows that left his much bigger rival sprawled on the canvas.
Browne had weighed in at 117.08kg, compared to Gallen at 102.2kg, and was the favourite for the bout, though most of the betting money had been placed on Gallen.
Gallen (11-0-1, 6KO) has the biggest scalp on his blossoming boxing career, and compared this to his NRL premiership with Cronulla Sharks in 2016.
"I don't know why but all today - I didn't say this to anyone - but I said 'I'm going to win this in the first round, I'm going to knock him out in the first round'," Gallen said.
"When I hurt him, I just jumped on him.
"When I got the opportunity to throw [the overhand right] I did, and I felt it crack, I knew I got him, I knew I hurt him.
“I’ve been training to be a boxer for eight to 10 months.
“It’s amazing what you can do when you put your mind to something.
“The more I trained, the more I sparred, the better I became at boxing and it showed tonight.”
Browne (29-3, 25KO) showed none of the scary power that took him to a WBA heavyweight title in 2016, and there should now be serious questions around his planned fight against Australian champion Justis Huni.
Gallen is off contract with promoter No Limit, but said he hoped to continue the partnership beyond this fight, and believes he can continue boxing for another two years as bouts against Sonny Bill Williams, Huni and a rematch with AFL legend Barry Hall loom on the horizon.
Questions had lingered about the quality of opposition Gallen had faced thus far; having beaten largely rival footballers and an unfit Mark Hunt in his last start.
Browne was another level, although he looked woefully inept against an opponent that he enjoyed every advantage; power, height, reach and experience.
On the undercard, Liam Wilson maintained his undefeated record, but was made to work through a rugged 10 rounds by Francis Chua in the super-featherweight division.
Wilson (9-0, 6KO) won with superior speed and power, staggering Chua (8-2-1, 3KO) in the sixth round before the 36-year-old showed grit to put pressure on late.
Wilson, 25, revealed afterwards he’d hurt his right hand early in the fight.
Steve Spark survived a first-round knockdown to win his grudge match against Jack Brubaker via eight-round decision.
Brubaker dropped Spark with a short right in the opening round, but the Queenslander regained his legs quickly to dominate the rest of the bout.
Spark (12-1, 11KO) had stepped up from super-lightweight to win his debut bout at welterweight, while Brubaker’s record dropped to 16-4-2 (8KO).
Bruno Tarimo defeated Kye McKenzie to retain his IBF International Super-featherweight title while also claiming the vacant IBO Intercontinental strap with a relentless 10-round assault.
Tarimo was on McKenzie’s chest for the entire fight and had his opponent rocked in the seventh round, while continuing to pepper him with a body barrage.
Tarimo moved to 26-2-2 (5KO) while McKenzie drops to 21-2 (17KO) after claiming a unanimous decision win.
Lenny Zappavigna made an impressive return after nearly three years out of the ring, blasting out Danny Kennedy in the third round.
Zappavigna, 33, dropped Kennedy with a powerful left hook.
Kennedy rose to keep fighting, however the brutal ensuing barrage of hooks to body and head saw referee Les Fear stop the bout.
Zappavigna (38-4, 28KO) is chasing a fight against former world champion Jeff Horn.
BELOW: RE-LIVE ALL THE ACTION FROM GALLEN V BROWNE IN OUR BLOG
Updates
Here we go! Come on Big Daddy!!!!!! As a Queenslander, but more importantly, a boxing fan, I hope Lucas Browne KOs Paul 'pigpen' Gallen.
Both men making the walk to the ring. Geez Gal looks really nervous but he'll bring it. The bloke doesn't mind the big moment. A six rounder because Gal couldn't hack it.
Big Daddy wants Shark fin soup!
And we're underway. Small slip from Browne but he's measuring with the left BUT DOWN GOES BROWNE! GAL DROPS BROWNE WITH A SHORT RIGHT HAND.
Done again! This is crazy! IT'S OVER! INCREDIBLE! PAUL GALLEN SHOCKS THE WORLD.
Incredible performance, incredible display. Unbelievable. Paul Gallen just turned it on.
PAUL GALLEN ON THE WIN
"I knew it was gonna go like that. I said to myself all day and to my team that I'd knock him out in the first round. I've been training to be a boxing for the last 10 months. It's amazing what you can do when you set your mind to it. I tore my bicep ten weeks out from the fight so it's amazing what you can do when you put your mind to it.
IS THIS HIS BEST MOMENT?
On an individual level it is … but it's hard to be humble after something like this but I will be … Lucas Browne isn't a bad bloke and I'm proud I've beat a champion like him."
ON THE HATERS
"All the haters will find a reason to hate Paul Gallen."
WHO'S NEXT
"I'm a prize fighter I'm not here to win belts, I'm here for fights the public want and make bank."
This bloke is kidding himself. Roberto Duran-esque. See ya champo
Ugliest fight of the night but still good fun.
Wilson turning it on in the last round. This'll go to the judges and I reckon Liam Wilson will be better for it.
Some serious bad blood, cuts, and, as I suspect, bad scoring … but let's hope not.
99-91 Wilson (my score) OFFICIAL SCORECARD: 98-92, 97-94, 97-94
Just more of the same here – Wilson has no right as Chua walks him down.
Wilson lands four clean shots though.
89, 82 Wilson
Yeah ya crazy, champo.
OH! That's a shocking cut and it came from head clash.
WOW. Wilson gestures to the referee that Chua hit on the back of the head but to no avail and Chua pounces, landing several clean punches.
Chua is a physco. Wilson's right hand is non existent and Chua can sense it. Ugly, ugly fight but very enjoyable at the same time. Easily Wilson's toughest fight to date.
79-73 Wilson
Someone finishhhhhhhhes this. Conformation Liam Wilson has an issue with the right hand. Let's see how this plays out.
Geez … they both trade punches – twice. Lovely combination inside from Wilson.
Sloppy round from both men. CHUA CUTS WILSON! But it's not enough to steal the round.
70-63
Ben Damon questions whether there's an issue with Liam Wilson's right hand as he seems to have put it in the holster.
Chua looks a different fighter – has barely thrown a punch in this round. The energy has drained from the little baby energiser bunny.
All the intensity has drained out this fight but Wilson again turns it up before the bell.
60-54 Wilson
Chua the wind-up toy keeps firing those little pistons and Wilson's bleeding from the beak.
Reckon Wilson wants some rounds in the bank here? He's done it before … not to take anything away from Wilson.
Chua just touching Wilson now. He's gassed hard but he'll last another round.
50-45 Wilson (Chua may have snuck a round or two)
Chua ripping to the body but Wilson's punches are causing damage where Chua's are not.
Fighting in the phonebooth here. Wilson is talking to Chua's corner now. Supremely confident.
Might give this another round or two before Chua's corner or the ref calls it.
Aussie undercards just continue to deliver time after time.
40-36 Wilson
"You have to take this MF this round with big overhands." That's the corner of Chua.
Chua is a little animal! He's not gonna die wondering. The small fella may have just punched himself out halfway through the third going for the finish and Wilson is putting his foot on the throat.
OH! Wilson is just so precise with his punches. But Chua keeps coming. Looking like a forgone conclusion here though.
30-27 Wilson
