Mackay, who played 17 Origin games between 1989 and 1995, hailed the St George Illawarra second-rower as a key man to reignite the Blues hopes of ending Queensland's dominance next year.

Creagh scored in the 18th and 66th minute as NSW won 28-16 to ruin Queensland's hopes of a series whitewash on Wednesday night.

Mackay said the 24-year-old was just starting to discover the magnitude of his ability.

"He's the best back-rower in the comp and he's been outstanding in every (Origin) game," he said.

"Even in the second game, which was the worst for the whole team, I thought he still played well.

"I think Benny has started to realise he is as good as he is, he's a great line runner, he can offload and make breaks himself.

"He's going to be around for a long time to come for NSW that's for sure."

A lock or centre, Mackay played 108 games for St George and three seasons for the Steelers before being part of the joint venture club's first season in 1999.

He was also part of four Origin series wins, including the Blues' three consecutive triumphs between 1992 and 1994.

While Queensland's victories in Melbourne and Sydney led them to a history-making fourth consecutive title this year, Mackay lamented what could have been for the Blues after their stirring win in game three.

"I just look at that series as a lost opportunity for NSW," he said.

"(NSW) showed great passion (on Wednesday) and you think even back to game one, the Blues were all over them until (Queensland) got a try against the run of play and it deflated them.

"That win will do wonders for the players like Creagh and Justin Poore, who have been there the whole series."

Mackay also heaped praise on Dragons prop Poore - destined for Parramatta next year - claiming he too had a bright future in Origin. "He used to run at the line like a bit of a madman, but the defenders could often turn him on his back and slow the play-the-ball," Mackay said.

"But he's quick on the ground at the ruck now and I think he's shown he is worthy as an Origin player as well. It's a pity the Dragons have lost him, because I think they'll realise what they have lost at the end of the season."