Premier Division: Cork City 4-2 Derry City
Derry slumped to a fifth defeat in six Premier Division games as champions Cork moved top with this Turner's Cross victory.
Karl Sheppard headed in an early Cork opener and the captain drilled in a second goal early in the second half.
Derry levelled with two goals in four minutes with Ronan Curtis firing in before Ronan Hales smashed home.
Cork were quickly back in front through Kieran Sadlier's free-kick and Graham Cummins slotted in the fourth.
The hosts netted with their first chance on seven minutes as Sheppard connected at the near-post from a Cummins cross to guide the ball past keeper Gerard Doherty.
Fourth-placed Derry recovered from the early setback and settled in to the game but they rarely threatened, with Aaron McEneff firing over with their best first-half opening.
Sheppard completed his double in the opening seconds of the second half by hitting the bottom corner after being played in by Garry Buckley.
Kenny Shiels' side produced an impressive response, creating half chances before stunning the Leesiders with two quick goals.
Curtis, playing in his penultimate Derry game before moving to Portsmouth, wrong-footed keeper Mark McNulty with a 20-yard effort to find the net after 65 minutes.
Derry now had the momentum and Hale controlled at the back-post before delivering a blistering shot into the roof of net.
However, Cork were back in front two minutes later as Sadlier's free-kick got through a poor Candystripes wall and flew beyond Doherty.
Hale almost equalised when his strike curled just wide but hopes of a comeback fizzled out after Cummins netted eight minutes from time.
The striker headed onto the bar from a long ball and he pounced on the rebound to stab in and make it 10 wins from 10 home games for Cork this season.
What they said
Derry boss Kenny Shiels said: "Poor defending - it's down to that. That's what killed us, elementary basic mistakes.
"There were a lot of good performances and I thought we were returning to something like what we can be.
"We get back to 2-2 and we were the better team at that stage and then the wall breaks at a free-kick. I couldn't believe it, it was really disappointing.
"And the last one was a joke goal. I can't believe why people were not taking responsibility."