Mack Hansen kicked a late, late penalty as the Brumbies maintained their unbeaten Super Rugby AU record with a last-gasp 22-20 win over the Reds.

Substitute Hansen was the home team's hero as he slotted over the game-winning kick on the final play of the game, punishing their opponents following an infringement at the breakdown.

The visiting Reds had looked set for victory after overturning a 14-3 half-time deficit thanks to a blistering 10-minute spell that saw them score 17 points.

Harry Wilson and Angus Scott-Young crossed for tries that were converted by James O'Connor, who also added a 50th-minute penalty to extend his team's advantage.

However, the Brumbies - who saw Folau Fainga'a touch down twice in the first half - closed the gap when Connal McInerney scored out wide in the 75th minute of a see-saw battle.

Hansen missed the conversion but was on target when presented with another opportunity after the final hooter, his long-range three-pointer completing the comeback.