Kevin Lasagna grabbed a late leveller as 10-man Carpi held Serie A title hopefuls Inter Milan to a 1-1 draw at San Siro.
The substitute striker, who was playing amateur football for Este less than two years ago, emerged from the bench to cover the expulsion of Lorenzo Pasciuti with a stoppage-time equaliser.
Rodrigo Palacio had earlier scored his first league goal of the season but it was not enough for previous leaders Inter, whose failure to win saw them slide into fourth place.
They did not start well, with Carpi twice going close to scoring through Jerry Mbakogu and then Matteo Mancosu in the early exchanges.
Palacio stepped up to the plate as the half-hour mark approached, the Argentinian testing Vid Belec with a header before breaking the deadlock as the interval drew nearer.
An Inter counter-attack allowed Palacio to turn Ivan Perisic's pass into an empty net.
The Nerazzurri remained dominant yet wasteful when play resumed, with Perisic's sighter proving easy for Belec to deal with.
Carpi retreated and it was not until the 82nd minute that Belec was forced into action again, the Slovenian goalkeeper doing remarkably well to keep both Palacio and Felipe Melo at arm's length.
The visitors thought any hopes of levelling had disappeared when winger Pasciuti left them a man light by fouling Miranda to earn a second yellow card.
But they were mistaken as substitute Lasagna made an historic impact with a left-footed drive past Samir Handanovic two minutes into stoppage time.