MIAMI — Munetaka Murakami, it turns out, was due.

Murakami, the star Japanese third baseman who owns the nation’s home run record and is coming off a Triple Crown, struck out in his first three plate appearances of Monday night’s World Baseball Classic semifinal. But he came through when it mattered most, delivering a two-run double in the ninth inning that sent Japan to a thrilling, 6-5 walk-off victory against Mexico at a sold-out LoanDepot Park.

Japan, which won the first two World Baseball Classics, in 2006 and 2009, will face reigning champion Team USA in the finale Tuesday night.

Japan fell behind Mexico early when Roki Sasaki, the 21-year-old pitching sensation, left a splitter up to Luis Urias for a three-run homer in the fourth inning. Japan’s hitters weren’t able to muster much offense against Patrick Sandoval, the Los Angeles Angels left-hander who allowed only three baserunners in the first four innings. But Japan’s offense finally came alive late.

Masataka Yoshida tied the score at 3 with a three-run homer off the concrete beam beyond the right-field foul pole in the seventh off JoJo Romero. Mexico took the lead again with RBI singles from Alex Verdugo and Isaac Paredes in the top of the eighth, but Japan added on another run in the bottom half and came all the way back against Giovanny Gallegos in the ninth.

Shohei Ohtani led off with a double to the right-center gap, showing rare emotion as he reached second base and signaled toward his dugout. Yoshida followed by drawing a walk, and Murakami launched a 94 mph fastball down the middle to deep center field, scoring the two runs that once again sent Japan into the championship.

It was the ninth walk-off hit in World Baseball Classic history and the first that occurred in the semifinals.