Haji Wright's hat-trick sent Coventry City back to the top of the Championship with a deserved win over Middlesbrough.
Just seven days after losing their long-held lead to Boro, the Sky Blues regained it at the first opportunity with a display full of energy and effervescence.
USA forward Wright had only managed two goals in his previous 19 games but he chose the ideal night to return to top form.
He had already headed one against the post when he scored midway through the first half before adding a second 10 minutes after the break.
Riley McGree halved the deficit with a fine finish for the Teessiders, before Matt Targett conceded a penalty for handball 17 seconds after play had restarted.
Wright stepped up to put it away and seal a huge victory for Frank Lampard's side as they climbed back into first, one point above their opponents.
It ended a run of six straight wins for Boro, whose miserable record against the Sky Blues now extends to seven losses in a row.
Coventry had opened up a 10-point cushion with a 4-2 success at the Riverside in November, only for Boro to turn the tables and establish a two-point lead heading into this game.
The visitors had really built momentum in the past few weeks, whereas the Sky Blues' winter stutter of four wins from 13 games either side of the festive period had started to become a cause for concern.
That contrast was reflected in the line-ups with Boro unchanged while the Sky Blues had four alterations from the disappointing goalless draw with Oxford United.
One of those brought back in was Wright and what a difference he made.
With just over 90 seconds played, he headed against the post from Tatsuhiro Sakamoto's in-swinging cross, but he made no mistake when the next chance came his way, steering his effort under Sol Brynn after more fine work from Sakamoto and then Jack Rudoni.
Having begun the season with nine goals before the October international break, the 27-year-old's dip was a sign of how difficult things have become for his side as autumn turned to winter.
Boro's cutting edge missing
Having taken 31 points from 14 games since self-confessed Lampard fan Hellberg replaced Rob Edwards in November, their attacking play in the first half had lacked some of the cutting edge seen in their recent winning run, despite having more than 60% of the ball.
Morgan Whittaker put a free header over straight after the interval while Hayden Hackney's tame shot on 55 minutes was their first on target.
But that inadvertently set the Sky Blues up to double their advantage with a goal that was throwback to football in the 1970s and 1980s.
From goalkeeper Carl Rushworth's long kick out of his hands in one box, Wright bullied Luke Ayling out of the way and fired into the far corner inside the other.
McGree gave Boro some hope but they did not give themselves a chance to test any Coventry nerves as from the very next attack as play resumed, Targett sloppily put his hand out to block substitute Josh Eccles' cross.
Wright stroked it into the bottom corner for his second Sky Blues hat-trick after one against Sunderland last March, and it is now six goals in five games against these opponents.
Substitute Jeremy Sarmiento hit the inside of the post for Boro late on but they were unable to prevent Coventry from completing a vital league double.
What next?
There are only five days before both sides are back in league action on Saturday.
Restored leaders Coventry go to West Bromwich Albion (12:30 GMT) before second-placed Middlesbrough welcome Oxford United (15:00).
'Energy and organisation immense' - Lampard
Coventry City manager Frank Lampard told BBC CWR:
"It was a big performance from minute one all the way through. The energy of the team was immense, and the organisation.
"It's a really difficult game against Boro, they're in great form, they've got good players, they're trying to play through you constantly and our players gave everything and got what they deserved out of the game.
"In games like this where it's tight, two good teams going against each other, it's so important to be clinical in the right moments.
"It sounds simple but we haven't been so clinical in the last period and that leads to the results we've had.
"Tonight we were clinical and I think we deserved it."
'Terrible goals to concede' - Hellberg
Middlesbrough head coach Kim Hellberg told BBC Radio Tees:
"It's a weird one because I'm a little bit disappointed first half not taking the ball forward.
"We end up not getting out with the ball, inviting them to duels and they were better than us in the first half. 1-0 was fair.
"The second half in general was very good from us.
"We created a lot of opportunities and we had two good chances but ended up conceding with a kick behind our line that bounced in our penalty box and it's a terrible goal to concede.
"We built momentum again, scored to make it 2-1 and had a lot of energy for that last part of the game and then it's a handball from nowhere.
"You cannot give away those type of goals to a very good team.
"Terrible timings, terrible goals. They don't have to play in our half but they've almost got two goals from never being there."