TOKYO, Japan (AFP) — Shohei Ohtani admitted he was "nervous" playing in front of a packed Tokyo crowd as the Los Angeles Dodgers started the new Major League Baseball (MLB) season with a win on Tuesday.

The Japanese baseball superstar delivered two important hits as the World Series champion Dodgers beat the Chicago Cubs 4-1 in front of over 40,000 fans at the Tokyo Dome.

But Ohtani, a national hero in Japan, said he needed time to feel his way into his first MLB regular-season game in his home country.

"It's been a while since I've been this nervous playing a game," the 30-year-old said.

"It took me a couple of at-bats to get into it but I was glad that I was able to do well in the later part of the game."

The series has been eagerly anticipated for months in Japan and excitement was at fever pitch at the start of the game.

Dodgers manager Dave Roberts said the occasion left its mark on the normally ice-cool Ohtani.

"I don't think I've ever seen Shohei nervous, but one thing I did notice was how emotional he got during the Japanese national anthem," Roberts said.

"That was telling."

The Dodgers' Japanese starting pitcher Yoshinobu Yamamoto struck out four batters in five innings to come out on top in his duel with Chicago counterpart Shota Imanaga.

It was the first time two Japanese starting pitchers had ever gone head to head on MLB's opening day.

"The demeanor he has on the mound, even if he gives up a run he's still calm," Ohtani said of Yamamoto.

"He was able to grow into the game."

The action got underway after a Pokemon-themed opening ceremony that featured an appearance by Japanese world champion boxer Naoya Inoue.

Ohtani stepped up to the plate to start the game but the first pitch whistled past him for a strike before he grounded out to first base.

The Cubs had taken a one-run lead by the time Ohtani came back to bat and he again failed to get a hit, lining out to second baseman Jon Berti.

Ohtani got his first hit off reliever Ben Brown and it gave the Dodgers the spark they needed as they scored three runs in the fifth inning to take the lead.

Ohtani struck out in his fourth at-bat but got another hit in his fifth as the Dodgers added another run.

"The biggest challenge was that I had only ever used the home team's clubhouse at Tokyo Dome, never the away sides," Ohtani said.

"That meant I didn't have access to the batting cage that I like but I think I was able to deal with it."

Imanaga pitched four hitless innings but the Cubs fell apart when he was relieved by Brown.

"I had two missions for the game — one was to play well and the other was for the team to win," Imanaga said.