Ancelotti hails Bale impact
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 as his free-kick deflected in off Alberto Moreno for the second.
Cristiano Ronaldo then went onto score a hat-trick and Karim Benzema twice, with Bale setting one goal for each of his strike partners as Madrid completed by far their most devastating offensive performance since Ancelotti took charge.
"Tonight everyone saw the real Gareth," Ancelotti 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."
Spanish international Xabi Alonso also made his first appearance of the season as a second-half substitute to round off a fine evening for the hosts.
Alonso has been blighted by a groin problem in recent months and also broke a bone in his foot back in August.
"We need to give him minutes, he was desperate to play and I think he is ready to play from the beginning.
"He has done everything he needs to be physically ready and he is a player that doesn't need the physical conditioning of others because he has so many other qualities."
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