Hernandez has been something of a forgotten man since joining the European champions on a season-long loan from Manchester United in September, but the Mexico international endeared himself to the Real faithful with great effect on Wednesday.
After a goalless draw in the first leg at Vicente Calderon last week, a tense quarter-final looked to be heading for extra-time until Hernandez scored the only goal of the tie two minutes from time at Santiago Bernabeu.
Hernandez was making only his seventh start due to the injury crisis at Real - with Gareth Bale, Luka Modric and Karim Benzema ruled out - and spurned several opportunities before his persistence paid off when Cristiano Ronaldo set him up with time running out.
Real had failed to beat Atleti in seven games this season and Ancelotti felt his side were worthy winners, paying tribute to match-winner Hernandez as his side beat Diego Simeone's men for the first time since winning the Champions League final in Lisbon last May.
The Real head coach said: "He [Hernandez] played really well with a lot of intensity. He deserved it because he didn't play a lot his season but when I told him to play he was ready. He trained really well and he was very professional and I’m happy for him."
He added: "We were strong at set pieces so we had total control and we had passion to find the right solution. We found that solution in the last minute, but that was our idea for this game.
"We played a good game and controlled the game from the beginning. We had good possession and didn't give them the opportunity to play counter-attack."
Atleti's cause was not helped when Arda Turan was sent off for a second bookable offence 14 minutes from time
