Jesus Castillo, meet Joe Carter.
Castillo gave Yucatan its first Mexican League championship in 22 years on Sunday night, hitting a walk-off homer in the 14th inning as the Leones outlasted visiting Monterrey, 2-1.
A 23-year-old infielder who hit one home run in 166 regular-season at-bats, Castillo opened the bottom of the 14th by depositing Miguel Rubio's 1-2 pitch over the right-field fence.
Yucatan won the best-of-7 final series, 4-1, to claim its third title and first since 1984.
Jose Vargas (4-0) recorded his fourth postseason win, shutting down the Sultanes over the final five frames. He allowed two hits and two walks while striking out four.
"I can't feel the arm, I can feel the heart," said Vargas, who was named MVP of the series. "This is something big in my career. The support of the fans and God make me stay and continue in the game. If the game went another inning, I would have went out."
Leones starter Oscar Rivera allowed one run on six hits and three walks while fanning eight in seven innings. Over the final three games of the series, Yucatan's starting pitchers gave up just one run on 11 hits over 18 2/3 innings.
Castillo's homer was the only hit allowed by Rubio (1-1), who issued a walk and struck out one in one inning.
The Leones took advantage of two miscues in the second to get on the board. Willie Romero reached on second baseman Miguel Flores's throwing error and advanced two bases on an errant pickoff attempt by Felix Heredia. Raul Sanchez followed with a sacrifice fly to forge a 1-1 tie.
Francisco Mendez plated Monterrey's only run in the second when he singled home Luis Garcia.
The Sultanes nearly regained the lead in the 11th when Garcia tried to score from second base on Carlos Rodriguez's infield hit. But he was gunned down at the plate by second baseman Oswaldo Morejon.
Ryan McConnell is a contributor to MLB.com. This story was not subject to the approval of the National Association of Professional Baseball Leagues or its clubs.