In a match that was postponed from Sunday due to torrential rain, Cagliari ended with nine men and Lecce with 10.
João Pedro and Radja Nainggolan put visiting Cagliari ahead 2-0 before teammate and defender Fabrizio Cacciatore was sent off for pushing a shot over the bar with his hand nine minutes from time.
Gianluca Lapadula converted the ensuing penalty kick then got involved in a shoving match with goalkeeper Robin Olsen that resulted in both players being sent off.
Marco Calderoni equalized in added time with an angled shot from inside the box.
Cagliari still stretched its unbeaten streak to 11 matches but was level on points with fifth-placed Roma.
Lecce remained one spot above the relegation zone.
Also, Spal and Genoa both remained in the drop zone following a 1-1 draw. Andrea Petagna put Spal ahead with a penalty early in the second half then Stefano Sturaro equalized for Genoa two minutes later.
END/AP/UNB/TZ