Brahim Diaz, Divock Origi and Rafael Leao fired Milan to a 4-1 win over Serie A new boys Monza – the club run by Silvio Berlusconi and Adriano Galliani.

The off-field power-brokers at Milan for over 30 years, owner Berlusconi and CEO Galliani have succeeded in taking Monza into the Italian top flight, but this was a reminder of how far they still have to come.

Diaz scored twice in the first half to put Scudetto holders Milan in charge at the break, and former Liverpool striker Divock Origi opened his account for the club to extend their lead.

Filippo Ranocchia reduced the deficit with a spectacular strike, but Leao had the final say, with Monza unable to reprise the level of performance that earned them a shock win over Juventus last month.

Diaz waltzed through the Monza defence in the 16th minute to open the scoring, surging from halfway before skilfully directing the ball past Michele Di Gregorio when coming under a last-ditch challenge.

Monza's Dany Mota should have levelled in the 28th minute but sent his close-range flying header straight at Milan goalkeeper Ciprian Tatarusanu.

Diaz doubled Milan's lead in the 41st minute when he collected a pass from Origi, stepped past defender Luca Caldirola and lashed a fierce right-footed strike across Di Gregorio and inside the left post.

Suffering with an apparent hamstring problem, Diaz was substituted early in the second half and was replaced by Charles de Ketelaere. Origi rifled the third goal in fine style in the 65th minute, lashing into the top-right corner from the edge of the penalty area.

Ranocchia pulled one back with a 30-yard free-kick in the 65th minute that Tatarusanu reached but could not keep out, before Leao swept home Milan's fourth from 15 yards in the 84th minute.