The winger has now scored two goals in the space of a week and looks a rejuvenated figure after two disappointing campaigns at Camp Nou
A solitary strike from the 24-year-old was enough to give the Liga champions victory and was the second time in a week that Sanchez has got himself on the scoresheet after his stunning chip in the 2-1 Clasico win over Real Madrid.
The Chile winger has struggled to replicate the form that won him a move to Camp Nou from Udinese two years ago but appears reborn under Gerardo Martino and the Blaugrana boss reserved high praise for the 24-year-old.
Martino told reporters after the game: "Alexis is an exceptional player who is able to create and win games. If there was any doubt about the quality that he had then he's proven how good a player he is. He has made and scored goals and we welcome it."
Much of the post-match talk surrounded the form of Lionel Messi, who has now gone four Liga games without scoring and appeared a shadow of his usual self on Friday night.
He said: "He is still the most important player in a team full of great players. If we keep winning, I'm sure he will begin to express himself again.
"I'm not worried. It's rare to score in 19 straight games and it's also rare that he goes three games without scoring. I'm sure he wants to score two, three or four goals a game but when his level is so high people think anything less than that is a problem. But for me there is no problem."
The win sees Barcelona move four points clear of Atletico Madrid at the top of La Liga, though Diego Simeone's side have a game in hand against Athletic Bilbao on Sunday.