Coventry City substitute Jack Rudoni scored twice in a thrilling win against Derby County to move Frank Lampard's side to within eight points of ending their 25-year Premier League exile.

Rudoni netted the winner in a see-saw contest 10 minutes from time to extend the Sky Blues' Championship lead to 11 points after Ben Brereton Diaz had twice pegged them back.

Frank Onyeka opened the scoring with his first Coventry goal before Rudoni restored their lead after Brereton Diaz headed in the first equaliser.

Brereton Diaz must have thought he had snatched a point for the promotion-chasing Rams when he made it 2-2 from the penalty spot before Rudoni settled it with his fifth goal in four games.

The victory makes it eight wins from nine for Coventry and they could secure promotion back to the top flight within the next fortnight.

The Rams, who have lost Rhian Brewster for the rest of the season following knee surgery, were bright, only for Coventry to open the scoring with a goal which was all about Onyeka.

The Nigerian midfielder, who joined on loan from Brentford in February, won possession before playing a one-two with Romain Esse on the right and curling his right-foot shot into the top corner.

Derby refused to buckle and deservedly equalised before half-time.

Centre-back Matt Clarke produced some great wing play, whipping over a fine cross from the left to the back post, which sailed over Sky Blues goalkeeper Carl Rushworth, for Brereton Diaz to head home.

The Rams were denied a second in first-half added time when Rushworth made a fine save from Jaydon Banel with his trailing right leg.

Coventry improved and Richard O'Donnell made a vital save from Josh Eccles after he had been played in by Joe Ward's poor backpass.

Lampard sent on Rudoni as part of a triple substitution and the midfielder delivered five minutes later when he coolly switched the ball on to his left foot to finish.

Derby levelled once again when referee Tom Nield harshly ruled Rushworth brought down Brereton Diaz and the forward, who has just returned from Auckland with Chile, converted the spot-kick for his seventh goal of the season.

Coventry showed the character of champions elect, and Milan van Ewijk crossed for the unmarked Rudoni to steer home his seventh goal of the season at the near post.

The Sky Blues are now 12 points clear of third-placed Middlesbrough and 14 points above fourth-placed Ipswich, although the Tractor Boys have two games in hand.

Derby are four points behind the play-off places with six matches to go.

Coventry boss Frank Lampard told BBC Radio CWR:

"It was hard earned and well earned. I felt it was a big test for us, against a good team in good form, play-off form, fighting for that we're fighting for.

"I'm delighted with the boys, they dealt with the game that was in front of them and, yeah, it's a big win."

On two-goal hero Jack Rudoni: "I said, 'are you ready for half an hour?' and he said 'I'm ready for more than that'.

"The biggest thing is not just his talent, but his hunger to come in and do stuff with his team. The first goal was incredible and then the other goal is a clinical finish. I loved it."

Derby manager John Eustace told BBC Radio Derby:

"I thought the whole team performance was very good. The three goals we conceded were really poor from our part and it's something, moving forward, we've got to stop doing, especially when we got to back to 2-2, I thought we could go and win it.

"We've conceded really sloppy goals, not doing the basics, tracking runners and not defending well enough.

"It's just not good enough. We could have a lot more points this season if we had done it for the whole 95 minutes and we spoke about that in the dressing room. But we still can't take away from the effort of the group today.

"You look at the players they're bringing on to make changes in that second half and we've still gone toe to toe with them. We're really disappointed we haven't won the game and the way we played in the first half was excellent."