Manchester Unitedβs Europa League clash went from bad to worse with 10 minutes remaining before they ultimately pulled off a 3-3 draw.
One match after earning his first club red card against Tottenham, captain Bruno Fernandes was again sent off.
United were down 3-2 in the 81st minute and the Portugal international attempted to go for a ball in the box but had his boot too high and earned a second yellow.
Fernandes was seen fuming with fellow international and Porto goalkeeper Diogo Costa over the decision, but it was too little too late as he headed down the tunnel.
The incident only added to the fact that United were initially ahead 2-0 in the first half.