Inter Milan missed the chance to take a share of the Serie A lead after Radja Nainggolan's late free-kick rescued a point from a 1-1 draw for Cagliari.
Walter Mazzarri's men could have been out of sight by half-time and heading for top spot - where Napoli and Juventus currently reside with 16 points each - but Rossoblu goalkeeper Michael Agazzi had a resilient afternoon at the Stadio Nereo Rocco.
Substitute Mauro Icardi finally found a way through for Inter with 15 minutes remaining but Nainggolan stepped up to grab Cagliari a share of the points in the final phases.
The Nerazzurri remain fourth in the table while Cagliari sit in the top half with seven points from six games.
By the end of the first half the Sardinians would owe Agazzi a huge debt of gratitude as the Lombardan keeper pulled off a series of fine saves.
Within minutes he was snaffling a low shot from Yuto Nagatomo before seizing on Fredy Guarin's long-range sighter.
Ishak Belfodil came knocking with a devious cross into the box and, after Agazzi had pushed it away, he pounced to deny Guarin a tap-in on the rebound.
Belfodil then got his head to a cross in a dangerous position. Agazzi made the save before the Algerian messed up an easy finish on the loose ball.
Inter keeper Samir Handanovic had been pinching himself to stay awake but was called into action on the half-hour mark as Mauricio Pinilla tried his luck from a corner.
Daniele Conti put in a block to spare Agazzi further exertions as Ricky Alvarez twisted to unleash an attempt and, minutes before half-time, Belfodil steered a header off target when picked out by Mateo Kovacic.
A slow start to the second half gave way when Alvaro Pereira burst into the box to pull the trigger on an easy finish but referee Gianluca Rocchi blew for a foul from Belfodil.
Rodrigo Palacio replaced the former Parma striker and was soon involved in a move that saw Pereira head over the Cagliari bar.
It was another substitute, Icardi, who made the long-awaited breakthrough in the 75th minute.
The Argentinian had replaced Alvarez over the interval and capitalised on a swift move between Palacio and Nagatomo to beat Agazzi with a close-range header.
Inter would not enjoy too much time in the lead, however, as Nainggolan squeezed home an equaliser seven minutes from time.
There was a touch of fortune about the Belgian's goal as his free-kick from distance took a mean deflection off Rolando's knee to unsight Handanovic.
The Nerazzurri were deflated but still went all-out for the winner as time ticked away, with Palacio particularly unlucky to miss the mark after dancing past two Cagliari defenders.