Skipper James O'Connor scored the winning try five minutes after the final hooter as the Queensland Reds beat the ACT Brumbies 19-16 to win the Super Rugby AU final in front of more than 40,000 fans at Lang Park in Brisbane on Saturday.

The biggest crowd for a rugby match in the world this year gathered anticipating the coronation of Brad Thorn's young side but the Brumbies almost spoiled the party with a mature display of percentage rugby.

Leading 16-12 but reduced to 13 men with two players in the sin bin, the reigning champions resisted surge after surge at their line in the final 10 minutes before the Reds finally moved the ball wide for O'Connor to score.

The last-gasp victory gave the Reds a second Super Rugby title a decade after their first, when they beat Thorn's Canterbury Crusaders at the same stadium - albeit this tournament only included the Austrlian franchises due to the coronaavirus pandemic.

The Crusaders earlier won the New Zealand tournament.