Panthers shock Broncos with big win at Suncorp Stadium

Trent Merrin of the Panthers is congratulated by team mates after scoring a try during the round 20 NRL match between the Brisbane Broncos and the Penrith Panthers. Photo / Getty Images.

Almost two years to the day since Brisbane sacked him, Anthony Griffin enjoyed a triumphant Suncorp Stadium return on Friday night as Penrith jumped into the NRL top eight with an upset 31-12 win over the Broncos.

With a shock victory in front of 30,878 fans, Griffin celebrated his first game with the Penrith reins in Brisbane since being told by the Broncos in July 2014 that he would be replaced by Wayne Bennett.

Penrith (9-9 record) overwhelmed a flat Brisbane by five tries to two to move to seventh on the ladder.

Griffin extends his remarkable run against Bennett, enjoying eight wins in 10 games against sides coached by the master mentor.

That includes their round-three 23-22 upset at Penrith. The sixth-placed Broncos (10-8) have slumped to their sixth loss in eight games and are in danger of stumbling in the finals race.

It was only Brisbane's second loss in seven games against Penrith at Suncorp Stadium.

It also marked back-to-back home defeats for the Broncos.

Penrith led 18-0 at the main break before piling on another two second-half tries including a 79th-minute effort by lock Trent Merrin.

Former Blues forward Merrin celebrated his 150th NRL game, running a remarkable 249m.

Queensland winger Corey Oates was the worst offender in the first half for a butterfingered Brisbane.

He knocked on in the lead-up to two of Penrith's three first-half tries and dropped the ball with the line open in the 20th minute.

Penrith centre Waqa Blake scored a controversial opening try.

Blake appeared to knock forward a Ben Hunt kick, only to regather and run 100m to score as disbelieving Broncos players looked on.

England's Zak Hardaker - the 2015 UK Man of Steel on loan from Leeds - scored his first try for Penrith in his fourth NRL game, running off Matt Moylan in the 39th minute.

Brisbane's display was summed up by a Hunt goalline dropout going out on the full, leading to Penrith's 35th-minute penalty goal.

Blake was helped off with concussion in the 27th minute after landing heavily contesting a kick.

Brisbane prop Josh McGuire might be in trouble for a 26th-minute high shot on Penrith winger Josh Mansour.

-AAP