Leaders Inter Milan missed the chance to move three points clear at the top of Serie A as Antonio Conte’s side were held by Atalanta.
Lautaro Martinez latched on to Romelu Lukaku’s pass to fire in his 17th goal of the season and put Inter ahead after just four minutes at the San Siro.
Atalanta dominated in the second half and Robin Gosens converted to draw the visitors level on 75 minutes.
Samir Handanovic saved Luis Muriel’s late penalty to deny Atalanta victory.
Inter extend their unbeaten run to 12 league games since their sole defeat of the season, against Juventus in October, but the reigning champions can move top with victory over Roma on Sunday (19:45 GMT).
Martinez had seen an effort cleared off the line by Berat Djimsiti midway through the first half, while Atalanta went close to an equaliser through Rafael Toloi shortly before half-time.
Atalanta, the league’s top goalscorers after winning their previous two Serie A matches by a 5-0 scoreline, deserved their equaliser, but Inter captain Handanovic produced a good save low to his right to prevent a late turnaround after Alessandro Bastoni had conceded an 88th-minute spot-kick.
Elsewhere, third-placed Lazio celebrated their 120th anniversary by recording a 10th consecutive Serie A victory.
Ciro Immobile’s 82nd-minute winner against Napoli ensured Lazio stayed in touch with the leaders – they are four points behind Inter.