Davide Moscardelli scored a flying header with virtually the last touch of the game to hand Chievo a 2-1 victory over 10-man Genoa on Sunday and knock their visitors off the Serie A summit.
Genoa had led the table on goals scored at the start of the day but ahead of the afternoon's later matches have now dropped behind Juventus and Udinese on goal difference.
They took the lead through Argentine Rodrigo Palacio but succumbed to an equaliser from Sergio Pellissier before substitute Moscardelli's dramatic late intervention.
Pellissier also missed a penalty after Genoa had Dario Dainelli sent off for a foul on the forward inside the box.
The first half involved little more than some tentative probing in which caution supplanted ambition.
The best chance of the half came when a slick Chievo move saw Pellissier's cushioned header play in Luca Rigoni but Sebastien Frey saved his snap-shot with an outstretched foot.
Genoa took the lead just three minutes after the restart as Cristobal Jorquera released Palacio who held off Santiago Morero before finishing under Stefano Sorrentino.
It was former AC Milan-target Palacio's sixth goal of the season in all competitions.
But the game changed just before the hour mark as Pellissier got beyond the Genoa backline and then went down as he seemed to have blown the chance with a heavy touch that was running through to Frey.
Dainelli was behind him at the time but even TV replays failed to confirm whether or not there had been genuine contact between the pair.
But the referee awarded a penalty and gave Dainelli his marching orders, and in fairness the defender didn't protest.
However, Pellissier opted to take a one-step run-up to the ball and his penalty was weak, with Frey plunging to his left to save one-handed.
Alberto Malesani immediately sacrificed Palacio for defender Andreas Granqvist.
However, Pellissier made amends when he lept highest to head home United States midfielder Michael Bradley's corner 16 minutes from time.
Chievo pushed for a winner but Frey made a sprawling save to tip away Gennaro Sardo's daisy-cutter.
However, with 15 seconds of time-added-on left, Sardo crossed from the right and Moscardelli directed a stooping header into the bottom corner.