The ball cannoned off the Mexican at Carrow Road and into the path of Danny Welbeck, after his fellow striker initially blocked a Ryan Bennett clearance, with the England international expertly rounding John Ruddy to bag the winner.
When asked to explain why the Reds have a better record on the road than at home, Hernandez pointed to the bad luck suffered during the 1-0 defeats to Everton and Newcastle in the early part of December.
"Perhaps we are getting a bit of luck that we didn't have in other games," he told MUTV. "For example, we're creating chances and scoring goals like the last one against Norwich when we had a little bit of luck.
"We take that luck as, in the first part of the season, we didn't have that. For example, against Everton, they did play a very good game and had one or two chances in the first half but we played better in the second half until they scored late on.
"We were in control of the game against Newcastle and created chances but didn't score. They had one chance and scored.
"So we're hoping to transfer our away record to Old Trafford."