AC Milan revived their hopes of reaching the Champions League last 16 with a 4-0 win at Dinamo Zagreb in Group E on Tuesday.
Back-to-back defeats by Chelsea in their two previous matches had left Milan with plenty to do to qualify for the knockout stages, but Matteo Gabbia's first-half header set them on their way to a crucial victory in Croatia.
Portugal forward Rafael Leao's solo run and finish early in the second half put the game beyond the home side, before French striker Olivier Giroud made doubly sure of the three points with a penalty just before the hour mark.
A late own goal put the seal on the second win of Milan's European campaign that moves them up to second place on seven points. If they avoid defeat next week against third-placed Red Bull Salzburg they will reach the last 16.
Milan's victory also means Premier League side Chelsea progress to the knockout stages as group winners after their 2-1 win away to Salzburg earlier on Tuesday, while Zagreb stay bottom on four points.
"I think it is clear that our growth continues with qualification," Milan coach Stefano Pioli said. "We have to play with our mentality and it is the next step, where we would show that we are doing better than last year.
"After fixing some positional problems, we resumed attacking with many players. It is an important victory and we know it. We must close out the job next week."
The Chelsea defeats left Milan with no room for error ahead of their trip to Croatia if they wanted to reach the last 16 for the first time since 2013-14.
They looked nervy early on as Zagreb, who beat Chelsea at home in their group opener, started well, but after Gabbia had headed his first-ever goal for Milan from Sandro Tonali's free kick, the win never looked in doubt.
Milan wasted several chances to make it two before Leao opened his Champions League account for the season with a slotted finish four minutes after the break.
If it had not been for home goalkeeper Dominik Livakovic, Milan, and especially Giroud, could have had a hatful, but the veteran striker had to settle for his well-taken penalty from his six efforts at goal in the match.
Robert Ljubicic's unfortunate own goal ensured Milan scored four in a Champions League encounter for the first time since beating Arsenal 4-0 at home in the last 16 in February 2012.
It was also the first time the Italian champions had scored four in an away match in the competition since beating Fenerbahce 4-0 in November 2005.