Lazio have effectively ended Inter Milan's hopes of salvaging European qualification from a difficult season with a 3-1 victory at the San Siro tonight.

Vladimir Petkovic's side needed three points to boost their own Europa League hopes and were gifted the opening goal on 21 minutes by calamitous home defending.

Samir Handanovic came out to meet a cross from Cristian Ledesma and punched the ball off the back of Sergio Floccari, who knew nothing about his opening goal as the deflection broke the deadlock.

Inter responded brightly and were level within 10 minutes as Ricky Alvarez beat his marker to guide home a towering header at the far post.

A deepening injury crisis for Andrea Stramaccioni's side got worse before the interval, with Jonathan stretchered off in some discomfort.

Alvarez then somehow managed to turn home a rebound unmarked from eight yards as the home side failed to make a dominant spell count.

Lazio took full advantage and edged ahead before the break as Andrea Ranocchia brought down Floccari inside the area.

Hernanes made no mistake with his powerful spot kick as the Aquile went into the break ahead.

Fredy Guarin missed from close range on two occasions after the break for Inter, before Alvarez fired well over the crossbar from the penalty spot.

The hosts were quickly punished for wasteful finishing at the other end as Ogenyi Onazi smashed home a volley from 25 yards.

Lazio held firm in the closing stages to move within two points of fifth place and European qualification.