Zlatan Ibrahimovic hit a brace as Internazionale beat struggling Ascoli to maintain their unbeaten run in Serie A and edge closer towards clinching their 15th Scudetto title.

The Sweden international twice got on the end of Adriano assists to help Roberto Mancini`s team extend their lead at the top to 18 points after Roma`s goalless draw at Fiorentina.

Massimo Bonanni`s injury time penalty meant no clean sheet for the visitors, but the points are all that count and Ascoli`s 15th defeat of the campaign leaves them rock-bottom, six points away from safety.

After last Sunday's 2-1 triumph against AC Milan in the city derby, Inter were quickly out of the blocks with Dejan Stankovic and Ibrahimovic looking particularly sharp up front.

Within five minutes, the lanky Swede tricked his way past Ascoli defender Riccardo Corallo, but his final touch saw him push the ball over Dimitrios Eleftheropoulos` goal from the edge of the penalty area.

At the other end, Michele Fini's darting run and cross from the left saw him deliver a teasing ball, which was well dealt with by the commanding Julio Cesar in the visitors' goal.

In the 16th minute, Maxwell`s shot from the left was from too acute an angle and ended up in the crowd.

Julio Cesar then did excellently to deal with Viktor Boudianski`s awkward shot from distance, before Sasa Bjelanovic hit a volley from 30 yards into the crowd as the action shifted from end to end.

Maicon then returned the compliment before Ivan Cordoba headed Luis Figo`s corner inches wide on the stroke of half-time.

At that stage the game looked evenly balanced with neither team looking to seize the initiative.

Figo then tried to inspire his team with a fine piece of footwork, but again the visitors were let down by poor finishing.

Another chance went begging on the hour mark when Adriano`s shot bounced inches wide, before the opener finally arrived in the 66th minute.

A fine cross from Adriano on the right picked out Ibrahimovic in the centre of the penalty area, and the first time shot gave Eleftheropoulos no chance.

Two minutes later Hernan Crespo's acrobatic effort was on target but not strong enough to trouble the Ascoli custodian.

However, the 74th minute brought the crucial second that all but sealed the contest.

In similar fashion to the first, Adriano again picked out the Swede, who this time had more time and controlled well before lashing the ball home from the left side of the penalty area.

Eight minutes from the end, an Adriano mistake allowed for a quick Ascoli counter attack which ended with a powerful Boudianski strike, but again, it flew straight at Julio Cesar.

Two minutes into injury time, Walter Samuel raised his foot too high on Bjelanovic leaving the referee no option but to award a penalty, which substitute Bonanni crashed home.