Aleksandar Tonev scored a hat-trick as Bulgaria strengthened their position in second place in Group B by hitting Malta for six in their FIFA World Cup qualifying clash in Sofia.

The Lech Poznan forward scored twice in the first half to put the hosts in command before Ivelin Popov got a third just after the break. Emil Gargorov made it four and Tonev completed his treble before Ivan Ivanov rounded off the scoring.

The win ensured Bulgaria remained Italy's closest challengers in the pool, while Malta stayed bottom and pointless.

The match was played behind closed doors after Bulgaria supporters were found guilty by FIFA of racist behaviour against Denmark in October, but the hosts had little problem asserting their superiority. They got off to the ideal start as they went ahead after six minutes.

Gargorov's ball in from the left was met by Tonev, who guided his shot into the bottom left corner. The hosts continued to dominate without really threatening to add to their lead, Georgi Iliev shooting wide from a Popov cross.

But Tonev made it two in the 38th minute with a low 25-yard shot which found the bottom corner. Popov added a third two minutes after the break, tapping home from Georgi Milanov's left-wing cross and a fourth arrived just seven minutes later.

Vladimir Gadzhev on the right made it, passing inside for Gargorov to convert. Tonev completed his hat-trick in the 68th minute with another effort from distance.  And Ivanov completed the rout 12 minutes from time with a close-range finish into the top corner.