Jese came on in the 27th minute of Wednesday's encounter at the Santiago Bernabeu after Colombian forward James Rodriguez had sustained a broken foot.
Rodriguez is expected to be out for at least two months and, along with Sergio Ramos, will miss the derby with Atletico Madrid on Saturday.
But Jese - who ruptured the cruciate ligament in his right knee in a UEFA Champions League tie with Schalke last March - immediately staked his claim for a place in the side in Rodriguez's absence,
The Spain Under-21 international scored what proved to be the winning goal nine minutes after his introduction, netting with a powerful close-range strike from Karim Benzema's deflected pass.
"I'm really happy because scoring always makes me delighted," Jese said. "It always gives you more confidence.
"When I came on the change happened so fast, it was really cold out there and Sevilla were committing a lot of fouls.
"I didn't warm up too well but everything turned out okay and we won, which is the main thing.
"It's also important to set up goals, but at the moment I needed one to keep on improving every day.
"We've been given two tough games in a week, today [Wednesday] we won and it was tough, but that's normal in this league - Now we are keen to beat Atletico on Saturday."
