NRL head of football Graham Annesley believes the high first-half penalty count on Wednesday night played a role in the thrilling finish to a match described as one of the best in Origin history.

Referees Gerard Sutton and Ashley Klein were widely criticised for a stop-start opening 40 minutes in which they awarded 12 penalties – the most of any half in this year’s Origin series.

However, the game came to life in the second half as both teams scored two tries apiece before James Tedesco snatched a late victory for NSW just 23 seconds before full-time.

In contrast to the 7-5 first half penalty count in favour of the Blues, Sutton and Klein awarded just one penalty against each team in the second term but Annesley insisted it wasn’t just a simple case of the referees putting their whistle away after the interval.

He said the players had been responsible for the penalties in the first half but were reluctant to infringe in the second term as they knew Sutton and Klein would take action.

"It has to be placed in the context that this was an Origin decider," Annesley said. "Both teams were trying to establish their dominance. And when that happens teams are going to push the rules to the limit, particularly in the play-the-ball and the 10 metres.

"If the referees just ignored that, the game degenerates into an arm wrestle for 80 minutes. I believe that the action that they took in the first half allowed the game to open up in the second half."

With the scores locked at 8-8 at half-time, both teams played a more expansive brand of football after the break in a bid to win the series.

The only second-half penalties - a hand in the ruck by Maroons forward Felise Kaufusi and an escort run by NSW second-rower Tyson Frizell – led to tries in the ensuing set of six.

"We were happy with the way the series was controlled," Annesley said. "Ultimately, the players determined the outcome, which is an important aspect for us."

Meanwhile, Origin III was the second-most watched program on Australian television this year, after the series opener at Suncorp Stadium. Origin II in Perth on Sunday, July 23, is the third most watched show in 2019.

The series decider was watched by 2.881 million viewers on the Nine network.

In total, 9.537m viewers watched the series, with Origin I drawing a television audience of 3.211m and Origin II attracting 2.808m viewers.