Matt O’Riley celebrated his new contract with a winner seven minutes into stoppage time as Celtic edged a 2-1 win over Motherwell after a dramatic finale at Fir Park.

Blair Spittal had levelled for Motherwell two minutes earlier after substitute Luis Palma grabbed his first Celtic goal in the 87th minute.

Fans were on the pitch after each of the late goals and missiles flew between the two sets of supporters after O’Riley’s winner.

The game had been on a knife edge throughout and Scott Bain, deputising for the suspended Joe Hart, made two good saves while the game was goalless.

O’Riley’s new four-year deal was announced on the morning of the game and he showed his worth by converting a cushioned volley at the back post following Greg Taylor’s cross.

The victory set Celtic up for the visit of Lazio in the Champions League on Wednesday and delivered another blow to Motherwell, who have now suffered narrow defeats against the top three in successive weeks.

Celtic had the bulk of the early possession but the only chances in the first quarter came from set-pieces. Spittal came close with an overhead kick and Liam Scales headed wide at the other end.

Motherwell were looking solid and Kyogo Furuhashi curled wide from 22 yards when Celtic did manage to pass the ball through the lines.

The home side had the best chance of the half when Spittal’s quick free-kick found Harry Paton’s run. Bain came out to block Paton’s shot with his foot and Celtic cleared the midfielder’s driven cross on the rebound.

Liam Kelly made his only save of the first half from O’Riley after quick feet from Yang Hyun-jun before Spittal got Motherwell in behind again. However, Brodie Spencer could not find a final ball to capitalise.

James Forrest replaced Yang at half-time and Celtic began to show more urgency in the final third. Taylor and Gustaf Lagerbielke could not make the most of half chances.

Motherwell raised their own tempo in possession and had the ball in the net after Bevis Mugabi challenged Bain at a high ball. Stephen O’Donnell hit the ball off Mugabi on the lone before knocking home the rebound and the offside flag went up. Mugabi’s challenge might have been penalised anyway if the wing-back had netted first time.

Taylor created Celtic’s best chance so far when he won the ball on the edge of the box and set up Daizen Maeda but the Japanese attacker shot over with only Kelly to beat.

Motherwell responded and Theo Bair volleyed straight at Bain before the goalkeeper’s feet again came to Celtic’s rescue when he blocked Spittal’s effort following Callum Slattery’s through ball.

The home side looked tired as the game entered the final 10 minutes and Kelly saved Forrest’s header after Palma’s cross.

Then came the drama. Palma curled just inside the far post from just outside the corner of the box as the ball whipped in between defender Dan Casey and Kelly. Fans spilled on to the track from behind the goal in the Tommy McLean Stand.

Motherwell found some energy and with plenty of players in the Spittal slotted into the far corner. Dozens of Motherwell fans were suddenly on the pitch and they were barely back in their seats when O’Riley struck and sparked an even bigger pitch invasion.