Leeds ended a winless run at Bramall Lane stretching back to their Division One title-winning season in 1992 as Hernandez’s 82-minute strike earned a 1-0 victory on Saturday.
The midfielder was on hand to fire into an empty net and punish a bad error from Blades goalkeeper Dean Henderson, temporarily lifting Leeds back to the top of the Championship.
United finished the weekend in second place after Norwich City regained a slender advantage but a tight win in Sheffield opened up a four-point gap over Middlesbrough in third. Fourth-placed West Bromwich Albion, who are five points back, play Brentford tonight.
Leeds have averaged close to two points a game under head coach Marcelo Bielsa and Hernandez believes a busy schedule before and over Christmas can consolidate the club’s prospects of ending a 14-year exile from the Premier League.
“It's important to stay in this position,” Hernandez said. "The next month is very important for us because we have a lot of games and the gap is too small between the first six or seven teams. If you lose two or three games in a row you can be relegated to sixth or seventh position.
"But if we continue in this way we can win a lot of games and this is the way we know. We know our style, we try to keep this style every game and I think it’s the best way to win games.”
Hernandez claimed his seventh goal of the term and his fourth in five games to see off Chris Wilder’s Sheffield United at the end of a closely-fought Yorkshire derby.
The match was heading for a goalless draw when Henderson played a weak pass to the feet of Leeds’ substitute Jack Clarke, allowing the 18-year-old winger to square the ball to an unmarked Hernandez in front of an unguarded goal.
Sheffield United’s Conor Washington struck the crossbar in injury-time as the Blades threatened to snatch a point but Leeds held out for a third straight league win.
“We always try to press high because sometimes the mistakes can appear,” Hernandez said. “We pressed high, the goalkeeper from Sheffield United made a mistake, we scored and got the three points. This is teamwork. It wasn't the best shot of my life but importantly it was a goal
“It’s a massive win. Sheffield United play very good and it's difficult to win in this stadium but we played a serious game, we did some massive defensive work and this was the key.”
Leeds’ celebrations were tempered by an injury to Liam Cooper which looks likely to sideline the club’s captain.
Cooper, who limped off in the first half on Saturday, could need surgery on a knee problem which head coach Marcelo Bielsa described as “serious”.
United’s defensive resources are already stretched and Finland Under-21 international Aapo Halme came off the bench to replace Cooper at Bramall Lane.
Hernandez said: “Obviously it's not good news. We need Liam and all of our players but if Liam is out then we have other players ready to play.”