If anyone was in any doubt about the dramatic effect a change of leadership can have, such feelings were surely dispelled at the Emirates last weekend.

Against all wisdom and soothsaying, the Blues beat the Gunners, in the process creating the longest current unbeaten run in this topsy-turvy Premier League, and lifting Chelsea to the giddy heights of 13th.

Guus Hiddink’s man-management, in contrast to the histrionics of his predecessor, is bringing the best out of Diego Costa, restoring the striker’s faith in himself and generating a hunger not seen since last season’s triumphs.

In the eyes of opponents and rival fans, he remains the devil incarnate… but for the Blues faithful he’s a hero again, with six goals in six games.

Arsenal, and manager Arsene Wenger, used to merely hate Chelsea. That’s now evolved into an even deeper loathing. Where Didier Drogba was once the Gunners’ nemesis, Costa now relishes the role.

A 1-0 win against a 10-man team, following Per Mertesacker’s early red card, may not be enough to catapult the Blues into the top half of the table yet, but if current form continues, progress is surely inevitable.

When Arsenal face Chelsea, they seem to succumb to rabbit-in-the-headlights syndrome. On Sunday they managed just one shot on target, with the Blues’ victory making it six league games on the spin between the teams where the Gunners have failed to find the net.

Petr Cech was unable to keep a clean sheet against his old team-mates, and – predictably – Cesc Fabregas had an excellent game, including a good shout for a penalty.

Now there’s the oddly welcome distraction of the FA Cup, and a trip to face the MK Dons, with Hiddink sticking to his policy of playing his strongest possible line-up.

Certain that he’s only a stop-gap gaffer, the Dutchman has no need to conserve resources or needlessly rest his stars. Fans love that.