The Brisbane Broncos will play a home sudden-death final against St George Illawarra next Sunday after beating Manly 48-16 on an afternoon where the match-ups between next week's semi-finalists was not known until the full-time siren.
The winner of the clash at Suncorp Stadium was known by at least the 60th minute, but whether the Broncos could secure a home semi-final was the issue.
The magic winning margin they were seeking was 24 points to leapfrog the Dragons into sixth.
The eventual winning margin of 32 points meant the Broncos finished with a differential of +56, the same as the Panthers.
Penrith's superior for and against percentages resulted in them staying in fifth position.
The Broncos had a 26-point margin in the 59th minute, then a 22-point gap in the 65th before a Jamayne Isaako try in the 70th minute wrestled the magic margin back.
Match: Broncos v Sea Eagles
Round 25 -
home Team
Broncos
6th Position
away Team
Sea Eagles
15th Position
Venue: Suncorp Stadium, Brisbane
Joe Ofahengaue sealed the deal in the 75th.
Brisbane's win was set up by an Anthony Milford masterclass and a four-try performance by winger Corey Oates.
Oates' four tries equalled the Broncos record held jointly by Wendell Sailor, Karmichael Hunt, Justin Hodges, Denan Kemp, Israel Folau and Steve Renouf, who achieved the tally on five occasions.
The Broncos started the game on fire with a Milford grubber finished by a flying Oates to take his season tally to 15.
Kodi Nikorima's running game was on song from the kick-off and after a well worked scrum move where he lined up in the backline, the Brisbane half eluded Joel Thompson's grasp to score.
The Broncos' pursuit of points was clear from the expansive play of Matt Lodge who acted as a second receiver and offloaded in tackles at will.
Manly, as they often do against Brisbane, made plenty of metres while in possession and a Shaun Lane try ate into the 24-point margin the Broncos were so desperately seeking.
Match Highlights: Broncos v Sea Eagles - Round 25, 2018
A 98m gallop by Oates after a Cherry-Evans bomb gave the Broncos a 20-6 lead, but a 20m cut-out pass by Cherry-Evans to put Brad Parker in frustrated Brisbane's quest to increase the margin as they took a 20-10 lead into the break.
Milford's masterful kicking game in 2018 was showcased again early in the second half when a deft grubber found James Roberts.
Milford excelled himself when he gathered a Jack Gosiewski grubber on his tryline, weaved his way to the 40m line and then grubbered for Oates.
Oates, at full pace, gathered the ball in one arm to race away and score a try that had the Broncos of the 1990s written all over it.
When Oates scored again in the corner in the 59th minute for a 36-10 lead the Broncos had a 26-point margin and a home final within their grasp.
Martin Taupau, impersonating a five-eighth, then put the ball on the toe for Jake Trbojevic to score and the Broncos were back chasing points again.
They found them, courtesy of 18-year-old forward David Fifita snaffling a loose Thompson pass and flicking a one-hander for Jamayne Isaako to race 55m and score under the sticks for a 42-16 lead.
Hearts were in Broncos fans mouths when an obstruction cancelled out a possible Daly Cherry-Evans try with seven minutes left, but when Ofahengaue slammed the ball down with five minutes on the clock a home semi-final had been secured.
Sam Thaiday farewelled the faithful in his final club game for Brisbane, but the popular veteran will be back next week for his last game at Suncorp Stadium.
Brisbane and St George Illawarra will clash on Sunday in finals football for the first time since Darren Lockyer's golden point field goal secured a 13-12 win for the Broncos in the 2011 finals series.
News & Notes: The Broncos lost forward Alex Glenn to a calf injury with Kotoni Staggs coming onto the bench... An accidental Joe Ofahengaue knee to the head ended Tom Trbojevic's afternoon 10 minutes before halftime... Anthony Milford played his 100th NRL game for the Broncos...Corey Oates' record equalling four tries for the Broncos took his season try tally to 18...Manly finished the season in 15th position on the NRL ladder...Crowd: 41,538.