Cardiff cemented their place in the Coca-Cola Championship play-off places after a convincing win over Derby in the last floodlit league match at Ninian Park.

The Bluebirds are leaving their home of 99 years in the summer, but they will be more confident than ever of seeing the lights switched on one more time for a play-off clash in May after goals from Roger Johnson, Gavin Rae, Jay Bothroyd and Eddie Johnson.

The win puts Dave Jones' side up a place to fifth in the table, but more importantly puts a five-point cushion between them and Preston in seventh.

Automatic promotion looks to be just out of their reach, with an eight-point gap to Birmingham in second, but hopes of beginning life in their new stadium in the top flight still remain.

Derby remain 17th in the table and six points clear of the drop zone with six games left to play.

The Rams had made the brighter start, with John Eustace having early appeals for a penalty waved away before forcing a fine save from Stuart Taylor in the Cardiff goal with an overhead kick.

And it was against the run of play when Johnson headed the Bluebirds in front after 16 minutes, rising to glance home a superb free-kick into the box from Peter Whittingham after Mile Sterjovski had fouled Rae on the right.

Michael Chopra then cut inside to force Stephen Bywater into a save, before Sterjovski came close to a leveller after 21 minutes when he chested down Barry Bannan's pass but could only flick his effort past the post.

Bothroyd had a goal disallowed after being set up by Chopra, who was in an offside position, while Rob Hulse headed over the top at the other end from a long throw by Paul Connolly.

Cardiff started the second half the brighter and Whittingham's follow-up after a Bothroyd shot was blocked went over the top.

The second period lacked much of the spark of the frenetic opening half, with Derby's best effort before the hour-mark falling to Eustace, but he headed well over the top from Gary Teale's cross.

But the game was soon dead and buried for the Rams with two goals in the space of two minutes.

First Rae collected Stephen McPhail's pass and he strode through from midfield before rounding Bywater and slotting into the empty net.

And almost straight away it was 3-0 as the Bluebirds won a corner, swung in by Whittingham, and the Rams failed to deal with it, with Bothroyd eventually poking home.

The game slowed down considerably after the third goal with a flurry of substitutions, but one of Derby's subs - Emanuel Villa - could have pulled a goal back from Robbie Savage's cross, but he headed a difficult chance over the top from 10 yards.

The Bluebirds netted four for the first time since December 2007 11 minutes from time when sub Johnson intercepted a pass from Andy Todd and ran through before smashing past Bywater.

Villa had a goal ruled out for a foul in the build-up and Kris Commons forced a fine save from Taylor with a 25-yard free-kick before the visitors did get a goal back from a Teale corner, with Johnson credited with the final touch for an own goal.

Teams

Cardiff Taylor, McNaughton, Gyepes, Roger Johnson, Kennedy,Rae, Whittingham (Burke 86), McPhail, McCormack (Parry 69),Bothroyd (Eddie Johnson 65), Chopra.

Subs Not Used: Heaton, Comminges.

Goals: Roger Johnson 16, Rae 61, Bothroyd 63, Eddie Johnson 79.

Derby Bywater, Connolly, McEveley, Nyatanga,Albrechtsen (Todd 65), Savage, Sterjovski, Teale, Eustace,Bannan (Commons 64), Hulse (Villa 63).

Subs Not Used: Price, Pearson.

Goals: Eddie Johnson 90 og.

Att: 18,403

Ref: Neil Swarbrick (Lancashire).