But the Maroons set the foundations for the win with heavy defence, scrambling to cover out wide and being almost impenetrable in the middle despite New South Wales having a majority of possession and territory and heavily outnumbering the home team 9-2 on the penalty count.
Queensland skipper Daly Cherry-Evans chased down a runaway Stephen Crichton for a try-saving tackle and Murray Taulagi held up another attacker over the line in two key momentum-stopping defensive efforts in the first half.
Queensland led 10-0 at the break via tries out wide to Holmes and winger Taulagi and doubled the margin with a second try to Holmes and another to centre Hamiso Tabuai-Fidow before Damien Cook crossed for New South Wales in the 57th minute in a short-lived revival.
Xavier Coates reached over and planted the ball just inside the corner post in the 65th to put the result beyond doubt and Jeremiah Nanai added a sixth try for the home team when he dived on a loose ball after Blues teammates Cook and Josh Addo-Carr collided in-goal.
“When we run out of the tunnel, there’s an energy that hits us and it’s like nowhere else in the world,” Cherry-Evans told the packed 52,400 crowd in Brisbane after his third series win in four years. “We’ve got plenty of footy in us, but it’s our ability to defend our try line that’s got us through both games.”
It was a frustrating night for the Blues, who lacked any cohesion or combination in the playmaking positions in the absence of regular halfback Nathan Cleary and were barely able to threaten in attack.
A last-minute melee led to Addo-Carr being sin-binned and five-eighth Jerome Luai sent off, leaving New South Wales with 11 players on the field for the last 30 seconds. Rookie Queensland fullback Reece Walsh was also sent off for his involvement in the skirmish.
Former Queensland fullback Slater only enhanced his status as a State of Origin great, having won eight of the 12 series he played in the annual series and now winning his first two series as coach.
Queensland, after scoring two late tries despite a one-man deficit in a 26-18 comeback win in Game 1 at Adelaide three weeks ago and dominating Game 2, heads to Sydney chasing the first 3-0 sweep of the series since 2010.