Ben Currie made a dramatic comeback from a 10-month injury lay-off with a try that kept alive Warrington Wolves' Betfred Super League top-eight hopes.
The Wolves trailed for most of the Grand Final rematch at the DW Stadium but Currie's 56th-minute try proved decisive as they pulled off a surprise 16-10 win over Wigan Warriors to ruin Sean O'Loughlin's 400th appearance.
The talented second-rower, who was in line to make his England debut before suffering a ruptured anterior cruciate ligament playing against Wigan in the Super 8s last September, had spent the first five months of the season watching his side struggle near the foot of the table.
But his eagerly-awaited return could be just the fillip as Warrington seek to ensure their top-flight survival.
Warrington will still be condemned to the Qualifiers if eighth-placed Huddersfield Giants beat bottom club Leigh Centurions on Friday while Wigan remain four points adrift of fourth-placed Hull FC as their title defence took a major jolt.
Wolves head coach Tony Smith said of Currie: "Aside from his try, I thought he was terrific. I thought he did everything that was asked of him and more. It showed what a class player he is. While ever there was a need for kick pressure, he was there.
"He didn't look as if he's been out all year. It's great to have him back."
Smith added: "Defensively I thought we were outstanding. Wigan are always going to ask questions of you so to limit them to 10 points was very good.
"I'm glad my boys were able to dig in for each other and come through. They've picked it up over the last few weeks and a couple of additions we made to the team helped us. Our kicking game was pretty good. I thought we did a great job on Sammy Tomkins at the back.
"It's a good time of the year to be getting confidence and form, whether we're playing in the Super 8s or the Middle 8s. What will be will be."
Wigan boss Shaun Wane said: "It was a massive game, the 400th for Lockers, and we had loads of reasons to win the game but I didn't see the desperation.
"We owed him a victory and we didn't get it. That's why I feel bad and really angry. I'm really disappointed and they know that.
"One hundred per cent Warrington deserved to win. They had too much enthusiasm for us which is something you can't practice.
"They had better line speed and ran harder. No flashy plays beat us.
"But we'll be in very early tomorrow and you'll see a different attitude against Leeds next week. We'll finish the season strong, no question about that."