AC Milan missed out on the opportunity to close the gap on Serie A's top five by falling to a shock 2-1 defeat to strugglers Empoli at the San Siro.Against the run of play, Levan Mchedlidze gave Empoli the lead towards the end of the first half before Mame Thiam added a second with just 20 minutes remaining.For all of their dominance, the hosts were particularly wasteful with Suso summing up their performance by seeing his penalty saved by Lukasz Skorupski.Gianluca Lapadula did manage to grab one goal back but Vincenzo Montella's side were unable to level the scores and now trail Atalanta in fifth by five points.It wasn't all doom and gloom for Milan, however, as Gianluigi Donnarumma produced another world-class save late on to prevent the scoreline becoming even more embarrassing.With the hosts pushing more men forward to try and find an equaliser, Empoli's Massimo Maccarone (formerly of Middlesbrough) managed to break away and had just Donnarumma to beat.A third goal looked like a mere formality when the Italian forward took his shot from 10 yards out - only for Donnarumma to deny him with an incredible stop - see the video below.It's a block he had absolutely no right to make and might even be one of the saves of the season!At 18, Donnarumma already has a huge frame and it certainly came in handy there.And it just serves as further evidence that the wonderkid is set for a very bright future indeed.It's just a shame that with AC Milan set to miss out on European football next season, we won't see Donnarumma be tested by some of the very best in the world more regularly for at least another year.Here's how Twitter reacted to his latest astonishing save: