Why Martin Odegaard Arsenal goal was disallowed against Porto as Mikel Arteta punished

 Martin Odegaard had a goal disallowed for Arsenal against Porto.

Arsenal captain Martin Odegaard saw his goal in the Champions League last-16 tie with FC Porto disallowed on Tuesday night after a foul on defender Pepe was spotted.

The Gunners thought they had gone ahead on aggregate at the Emirates Stadium when Odegaard tapped the ball into an empty net in the second-half.

Leandro Trossard had put Mikel Arteta's men 1-0 up on the night in the 40th minute after Odegaard's world-class pass unlocked the Porto defence. However, the Portuguese giants defended well in the second half to keep the tie level.

Halfway through the second half, Arsenal thought they had taken the lead in the tie for the first time when Odegaard scored. However, referee Clement Turpin immediately disallowed the goal on the field, despite Odegaard celebrating.

Replays showed that Kai Havertz had fouled Pepe in the build-up to the goal. The forward had entered a 50/50 with the defender and goalkeeper Diogo Costa but gained an advantage with a slight pull of Pepe's shirt.

The ball eventually fell to the on-rushing Odegaard but Turpin was quick to reward Porto with a free-kick. A brief VAR check didn't see any reason to reverse the on-field decision.

Mikel Arteta obviously didn't agree with the decision with him going into the referee's book for protesting the decision. The television cameras showed the Gunners boss demanding for VAR to overturn the decision.

Porto's head coach Sergio Conceicao was booked not long later after being left fuming with Turpin failing to reward his side a free-kick for a foul by William Saliba outside the area.