The England international, on loan from Liverpool, scored twice in a win that helped allay lingering fears of a relegation battle for the Hammers.
Having headed the home side in front from a first-half corner, Carroll's second was a sublime first-time volley having allowed the ball to drop over his shoulder from a free-kick with 10 minutes remaining.
In Allardyce's opinion, the goals were just reward for an all-round performance of the highest quality from the 24-year-old.
"His performances have equalled that, but he has not put the ball in the back of the net as regularly as we would have liked," Allardyce asserted.
"Getting a brace today is fantastic for him, and today showed what he is all about.
"He's not just strong in the air, as people perceive is his only strength, it's the quality on the floor, the hold-up play and then the technique on the volley, as we saw, was outstanding.
"It was a world-class finish, nobody can take that away from him, it was outstanding."
Allardyce had talked before the match of a need for five points from the remaining nine games to secure a place in the Premier League, a matter that is of even more importance with a move to the Olympic Stadium pencilled in for 2016.
"With Wigan winning and closing the gap it was a very important win for us today, it puts us back in 11th spot so we're moving back up the table. We've been hovering around there all season, so it shows the consistency," he added.
"There's a new future ahead for West Ham, and it's a focus to build for that future. I only focus on the next game, get the club in a position to re-plan and organise for next season. We're not quite there yet, but we're looking very comfortable."
Allardyce also confirmed that substitute George McCartney had hobbled off late on with a recurrence of a knee injury that had kept him out of action for four months.