Viktoria Plzen scored two late goals they drew 2-2 against AC Milan in their Champions League Group H match in the Czech Republic.
Milan striker Pato fired the opener in the 47th minute and set up strike partner Robinho for the second as the Rossoneri continued their strong run of form.
The Serie A club looked to be cruising to a win but David Bystron pulled one back for Plzen in the 89th minute and Michal Duris equalised from close range in injury time.
Milan had already secured progression into the knockout stages behind Barcelona and approached the game in buoyant mood after they extended their unbeaten run in the domestic league to eight games following the 2-0 win over Genoa at the weekend.
The draw means Plzen have guaranteed Europa League football in the new year as BATE Borisov were beaten 4-0 by Barcelona in the other game, meaning the Czech side finished third in the group.
Both sides had good chances in the first half but neither side could break the deadlock until Milan's quickfire double strike after the break.
Pato's shot went wide in the ninth minute before Plzen midfielder Vaclav Pilar blasted his shot over the bar from Pavel Horvath's corner.
Clarence Seedorf delivered a testing corner for Milan just before the half-hour but Pilar made a calm clearance at the near post to deny the Serie A side.
Mattia De Sciglio then blasted over the bar from 30 yards before Plzen missed a chance at the other end when Milan goalkeeper Marco Amelia caught Frantisek Rajtoral's strike.
Seedorf also fired over the bar from range before Pilar and Milan Petrzela were both off target for the home side as the first half drew to a close.
Pato scored two minutes into the second when he linked up with Robinho before rounding the keeper and sliding the ball into the open net.
The strike partners reversed roles a minute later when Pato set up Robinho for the second to give Milan a comfortable lead.
Robinho beat Plzen goalkeeper Marek Cech with a strike from the middle of the area which flew into the top of the net.
Milan were now dominating the clash, with Seedorf forcing a save from Cech with another 25-yard effort before Pato struck the post from the right of the box before Cech managed to save his follow-up effort.
Plzen midfielder Petrzela hit the post in the 57th minute before Rajtoral's long-range effort missed the target soon after.
The home side finally got onto the scoreboard with one minute remaining thanks to Bystron's close-range strike.
And Duris' equaliser two minutes into injury time completed the comeback as the Czech side secured a place in the Europa League round of 32.