Milan, sitting 10th overnight, hosted Inter at their shared San Siro ground desperate for three points to maintain their Europa League bid following wins earlier in the day by direct rivals Torino and Parma.

The hosts dominated an opening half in which Kaka struck the bar with a superb half-volley, but it took De Jong's bullet header from a Mario Balotelli free kick in the 65th minute to finally spark the game into life.

Milan scored their first derby win since April 2011, when coach Clarence Seedorf still played at the club, to move up to provisional eighth ahead of Verona's visit to Lazio on Monday.

"We said we were going to fight till the death and although a lot of teams are still in contention, we took an important step tonight," said Seedorf.

"Inter played well but I think we just had the competitive edge and it was really nice to see the lads pull together and fight."

Inter remain fifth but their Europa League spot is not yet secure.

Coach Walter Mazzarri lamented his side's limpid approach to the game.

"We simply didn't play well," said Mazzarri. "We took the pitch knowing we needed to win but we just didn't have any fighting spirit. I don't like how we played at all."

Milan had the best of the opening exchanges although after a half-chance from distance by Adel Taarabt went astray Inter came close to breaking the deadlock.

Rodrigo Palacio skewed a shot wide of Christian Abbiati's upright after being sent through by Jonathan and then Yuto Nagatomo danced past two defenders at the left byline before delivering low for Palacio, with Abbiati down quick to block at his near post.

Milan almost had the breakthrough when Taarabt threaded a superb ball through the Inter defence for Paolo De Sciglio, but the right back's first-timer was into the side-netting.

De Jong was giving a battling performance in midfield and after stealing possession, set up Balotelli only for the striker to shoot wide from distance.

From an innocuous looking long ball from midfield on 41 minutes, Kaka held off two defenders to send a half-volley over Samir Handanovic and off the bar.

Kaka then saw his speculative angled shot from 20 metres fly just wide and the Brazilian then held off Esteban Cambiasso to send Taarabt clear on the right.

Although the Moroccan's cross missed Balotelli, Kaka came in late to send a first-timer just over.

Inter shaded the start to the second half with Matteo Kovacic a constant threat around the area, the Croatian unleashing one drive that was blocked by teammate Mauro Icardi.

Milan came close again on the hour when Phillipe Mexes headed just wide from Kaka's corner.

Eyebrows were raised minutes later when Balotelli stepped up to take an indirect free kick from a tight angle after Taarabt had been fouled.

But in a crowded area De Jong somehow found space to squeeze through and send a powerful header past Handanovic.

The goal sparked the match into life and moments later Inter striker Rodrigo Palacio broke free only to balloon his effort over.

At the other end a close-range shot from Kaka after the Brazilian had chested across down met traffic.

Milan had the momentum and after Balotelli sent a delightful flick into the box the hosts had the ball in the net when the striker's drive from distance deflected off Giampaolo Pazzini, who had replaced Kaka on 76 minutes.

Inter coach Walter Mazzarri sent Riccardo Alvarez, Fredy Guarin and Diego Milito on in the dying minutes.

Inter had a brief moment of hope when Pazzini gave away a free kick in the first minute of injury time, but Milito sent a glancing header wide.