Sanchez left Old Trafford in the summer to join Inter Milan on loan and made his full debut for the Serie A giants against Sampdoria.
He netted a quick-fire brace in the first half and it comes after he struggled at Manchester United.
The first goal may well go down as a Stefano Sensi goal, though Sanchez will feel aggrieved if he doesn’t get it.
The Chilean joined the Red Devils last January though scored just five goals in all competitions.
And after getting two for Inter, United fans were not happy with their own recruitment and staff.
One United fan wrote on social media: “Alexis Sanchez has just scored two goals in two minutes. We really do just make everyone s***e don’t we? #MUFC.”
Another added: “Alexis Sanchez scores on his first debut for Inter. Of f***ing course.”
A third posted: “Alexis Sanchez. more goals with Inter than with United already… I guess Utd does ruin players.”
A fellow supporter commented: “The deadwood seems to have come alive . Sanchez with 2 goals in 5mins meanwhile the firewood Rashford has 3 goal in play in 20 games . #peteacheratthewheel”
While one more added: “Sanchez banging the goals in whilst we can just barely beat Rochdale #MUFC #SAMINT.”
Another put: “So Alexis Sanchez already got 2 on his debut for Inter and we are relying on a 17 year with no premier league starts, fantastic management @olegs26_ole @Mike_Phelan_1 #WoodwardOut @ManUtd #mufc.”
But Sanchez saw red in the second half after picking up two yellow cards, the second for simulation inside the box.
And some United fans certainly saw the funny side of the forward’s eventful evening.
“Alexis Sanchez sent off for diving loooooooool,” tweeted one United fan.
Another said: “Haha Sanchez sent off oh dear.”
“Lmao Sanchez,” reacted another.
Inter Milan ended the match as 3-1 winners with Roberto Gagliardini scoring the third.