Madrid had qualified for the tournament between the top teams on each continent in large part thanks to Bale, who scored twice in the 3-1 win over Liverpool in May’s Champions League final.
Bale scored his first goal against Kashima just before halftime and added two more quickly after the break to decide the match.
“It’s an important victory,” Bale said. “We knew it would be a difficult game against a team that would make it difficult for us, so we just had to be professionals and get to the final.”
Madrid will next play host side Al Ain FC on Saturday, when the European champions will be heavily favored to claim a fourth club world title.
“I’m happy for the three great goals by Bale, and for the strength and consistency showed by the team,” said Madrid manager Santiago Solari.
Solari said that another world title would be “a prize for this team that has given its fans so much and accomplished the feat of winning three straight Champions Leagues. Adding three straight Club World Cups would be fantastic.”
Wednesday’s game was a rematch of the 2016 final, when Madrid needed extra time to beat Kashima 4-2.
This time they had no trouble.
Kashima had a promising start as Serginho shot just wide and Gen Shoji almost reached a corner kick that would have left him with a pointblank header in the third minute.
Madrid, however, took control and started probing the right side as Bale’s speed proved too much to handle.
Karim Benzema and Sergio Ramos sent headers wide before Bale exchanged a quick pair of passes with Marcelo to score off the far post in the 43rd minute.
Read Also: Gareth Bale’s son in Champions League mood
Bale’s second goal in the 53rd minute came after two horrible passes by Kashima defenders left their goalkeeper stranded and he added his third two minutes later after Marcelo found him alone in the box.
Bale was replaced by Marco Asensio, who later had to leave with an apparent leg injury.
Kashima’s Shoma Doi then closed the scoring with a goal in the 78th minute.
The match was interrupted in stoppage time when two fans ran onto the field toward Benzema and Marcelo. They were quickly removed by stadium security.
On Tuesday, Al Ain upset River Plate of Argentina on penalties.
Kashima Antlers 1-3 Real Madrid
Doi 78 (KA) Bale 44, 53, 55 (RM)
Kashima Antlers: Sun-tae; Nishi (Anzai 56), Seung-yhun, Shoji, Yamamoto; Endo (Leandro 83), Nagaki (Uchida 46), Leo Silva, Abe; Doi, Serginho
Real Madrid: Courtois; Carvajal, Varane, Ramos, Marcelo; Modric, Llorente, Kroos; Vazquez (Isco 68), Benzema, Bale (Asensio 60, Casemiro 74)
Referee: Pereira Sampaio (BRA)