Robert Acquafresca's first-half goal earned Cagliari a hard-fought victory at Bologna today which all but ensures they clinch Serie A safety but also sparks their European dreams into life.

Acquafresca headed in the only goal of the game on the stroke of half-time to leave Bologna even further in trouble.

Cagliari have now surpassed the 40-point mark - the target for avoiding relegation - and are just four points behind Roma who occupy the last Europa League berth.

Bologna remain two points off the relegation zone with nine games left to play.

Home coach Sinisa Mihajlovic had urged his players to pull a response out the bag following a hefty defeat to Juventus last week, and they certainly gave it their all in a battling game which saw six bookings in the first half alone.

The hosts came close to taking an early lead as Francesco Valiani played in Manuel Belleri who put in a good cross for Pablo Osvaldo only for the former Fiorentina striker - still searching for his first goal of the season - to head over the bar.

Cagliari also had an early chance as seconds later Acquafresca found himself one-on-one with Bologna goalkeeper Francesco Antonioli but the ball was scrambled away before he could unleash a shot.

Antonioli did even better in the 23rd minute as he had to look alert to dive swiftly across his goal to push Davide Biondini's rocket from the edge of the area out for a corner.

Just as it looked like the teams were going to go in at half-time with the score goalless, Cagliari took the lead when Acquafresca headed in a loose ball following a free-kick for his 10th goal of the season.

The goal had Mihajlovic kicking the bench in frustration, while Osvaldo was booked for his protests.

Acquafresca should have doubled his tally five minutes after the break as he controlled a long ball well under pressure from Salvatore Lanna but fluffed his shot which sailed wide.

Cagliari were in complete control of the game and it was thanks to Antonioli that Bologna were not losing by more and the goalkeeper was again on hand in the 54th minute to reach Michele Fini's cross a fraction before the lurking Jeda.

Nevertheless, the visitors should have doubled their lead when Carlos Matheu played a lovely long ball to Acquafresca on the wing who in turn crossed to an unmarked Fini in the centre of the area but his diving header flew wide.

Bologna's only real chance at the beginning of the half came on the hour mark but they wasted it as Adailton attempted to finish off a counter attack when he should have passed to Osvaldo in space.

The hosts could have got something in a final 10 minute flurry as first a scramble in the Cagliari area saw Nicola Mingazzini's shot rebound to Di Vaio who turned but fired into the side netting before Alessandro Matri dragged his effort just wide following a lovely cross from Fini.