Teun Koopmeiners’ disputed penalty kept Atalanta in the race for Serie A’s top four as AC Milan saw two points wrenched from their grasp.

Koopmeiners cancelled out Rafael Leao’s brilliant opener from the spot three minutes before the break with his 10th goal of the season after Olivier Giroud had been penalised for a high challenge on defender Emil Holm to secure a 1-1 draw at the San Siro.

That left his side two points adrift of fourth-placed Bologna with a game in hand at the end of a frustrating evening for Stefano Pioli’s men, who remain third, but are now 13 points adrift of leaders and city rivals Inter.

Milan could hardly have got off to a better start when Leao picked up possession wide on the left, skipped past Holm and them evaded Giorgio Scalvini’s challenge before curling a delicious shot across keeper Marco Carnesecchi and inside the far post with less than three minutes played.

However, it took a last-ditch 17th-minute challenge from Yacine Adli to prevent Koopmeiners from making meaningful contact with Charles De Ketelaere’s pull-back and defender Berat Djimsiti back-heeled an audacious attempt wide from the resulting corner.

Ruben Loftus-Cheek headed wide and Theo Hernandez saw a long-range strike deflected behind as the hosts responded, but the visitors were handed a way back into the game in controversial circumstances as the whistle approached.

Holm went to ground clutching his face after tangling with Giroud inside the Milan box and although replays showed the striker’s boot had connected with the defender’s armpit, referee Daniele Orsato was advised to review the incident and eventually awarded a penalty, which Koopmeiners converted with the minimum of fuss.

Ademola Lookman joined the fray as a replacement for De Ketelaere before the restart and Atalanta had a better balance about them, although the game became bogged down in midfield.

Loftus-Cheek whipped a 59th-minute shot straight at Carnesecchi after exchanging passes with Christian Pulisic, and the keeper had to make an instinctive save with his foot two minutes later after substitute Davide Calabria cut inside and drilled the ball towards goal.

Loftus-Cheek scuffed an attempt well wide after Leao and Adli had carved a path through the white shirts and Pulisic stabbed past the post after controlling Leao’s pass over the top superbly with the Rossoneri pushing for a winner.

Carnesecchi had to beat away Loftus-Cheek’s 77th-minute drive and then clawed out Leao’s toe-poke three minutes later with substitute Davide Zappacosta clearing Giroud’s follow-up off the line.

But Atalanta, who had won their previous five Serie A games and beaten Milan in both the league and the Coppa Italia this season, held firm to emerge with a point.