Aidan Sezer kicked an extra-time field goal as Canberra Raiders completed a brilliant turnaround to beat Cronulla Sharks 15-14 and secure a top-four finish.

On Paul Gallen's final home match of the regular campaign before retirement, his farewell to the Sharks' faithful looked to be going swimmingly when the home side took a 12-0 lead into half-time.

Ronaldo Mulitalo had charged over either side of Jayden Brailey's effort, but Kyle Flanagan – who will sign for the Sydney Roosters ahead of next season – could not add any extras.

Flanagan's profligacy proved costly after the break, with the Raiders mounting a wonderful comeback through Charnze Nicoll-Klokstad and Nick Cotric before Sezer kicked the first of three field goals to nudge the visitors ahead.

Chad Townsend delivered an immediate response with a field goal of his own two minutes later, and a second in point in quick succession looked to have sealed a vital win in the Sharks' push for a finals place.

But Sezer had other ideas and, after restoring parity in the penultimate minute to force extra time, he completed his hat-trick of field goals to clinch the golden point and ensure the Raiders' place in the top four.

The Sharks' position in the top eight is now under real threat heading into the final game of the regular season, and a showdown to make the finals will take place when they face Wests Tigers next time out.

Paul Momirovski scored a hat-trick in a 42-14 hammering of St George-Illawarra Dragons as the Tigers moved onto 24 points – level with Cronulla.

Momirovski was in inspired form, opening the scoring three minutes in before kicking the first of seven successful conversions.

Luke Garner got in on the act just after the half-hour, with Momirovski helping himself to two tries in quick succession following the interval.

Gareth Widdop pulled one back, but Benji Marshall, Luke Brooks and Elijah Taylor added gloss to a convincing victory which sets up a grandstand finish to the regular season.