Bale was making his first start at the Santiago Bernabeu and soon had his first home goal when he thumped in the opener on 13 minutes.
He then had a slice of luck 14 minutes later as his free-kick deflected in off Alberto Moreno for Real’s second.
Cristiano Ronaldo then went onto score a hat-trick and Karim Benzema twice, with Bale setting up a goal apiece for his strike partners as the 24-year-old completed the 90 minutes for the first time since joining the club last month.
“I felt good and completed the full game. After not having a normal pre-season it is important to pick up rhythm to be able to give my best,” he told Real Madrid TV.
“It was a great night. Obviously I needed time to improve physically, but I am very happy to have played the 90 minutes. That is very important for my fitness.
“We played very well tonight and hopefully we will have more games like this in the future.
“Now I need to keep improving and working hard to be at 100 percent as soon as possible.”
Victory moved Real back to within six points of Barcelona at the top of La Liga.
Madrid are in action once more against Rayo Vallecano on Saturday before travelling to face Juventus in the Champions League next midweek.
And with the worst of his injury problems appearing to be behind him, Bale is desperate be involved.
“It is a an exciting time. We have big games ahead and everyone is desperate to win them.
“We have a lot of confidence and I hope we can keep winning and playing like we did tonight.”
Bale’s performance was lauded by his coach Carlo Ancelotti, who believes his new star showed what he was truly capable of for the first time in a Madrid shirt.
“Tonight everyone saw the real Gareth,” he said.
“He played really well, showing fantastic skills. It takes time but it was a necessity, now he doesn’t have problems physically and he is improving his confidence so he will be very important for us in the future.”
Despite being delighted with the performance of his front three, though, Ancelotti was disappointed with how Real let Sevilla back into the game after racing into a 3-0 lead.
Ivan Rakitic’s penalty and Carlos Bacca made it 3-2 at half-time and Rakitic struck again and missed a penalty in the second-half as Sevilla exposed Madrid’s defensive frailties.
“It was a bit of a crazy game, we started very well and were 3-0 up. We then lost a bit of concentration and balance and the game was alive again.
“Offensively we played very well, we scored a lot of goals. We had a lot of good individual performances, especially up front.
“Obviously we need more balance to avoid problems going forward, but up front all three players were very dangerous.”