Wildcard game winner winning World Series: 2014 and 2019.

The second wildcard was added in 2012. The two wildcard teams play a sudden death single elimination game, which leaves them with disadvantages for the remainder of the tournament, including using their best starting pitchers to reach the wildcard game and/or in the wildcard game, immediate travel and not having home field advantage. Despite that, ...

2014: Both the Giants and Royals (89 wins) won their wildcard games and reached the finals.

World Series	4-3	San Francisco Giants over Kansas City Royals
NLCS	4-1	San Francisco Giants over St. Louis Cardinals
NL Division Series	3-1	San Francisco Giants over Washington Nationals
NL Division Series	3-1	St. Louis Cardinals over Los Angeles Dodgers
Wild Card Game	1-0	San Francisco Giants over Pittsburgh Pirates

Tm	W	L	W-L%	GB
Los Angeles Dodgers	94	68	.580	--
San Francisco Giants	88	74	.543	6.0
San Diego Padres	77	85	.475	17.0
Colorado Rockies	66	96	.407	28.0
Arizona Diamondbacks	64	98	.395	30.0

2019:

World Series	4-3	Washington Nationals over Houston Astros
NLCS	4-0	Washington Nationals over St. Louis Cardinals
NL Division Series	3-2	Washington Nationals over Los Angeles Dodgers
NL Division Series	3-2	St. Louis Cardinals over Atlanta Braves
Wild Card Game	1-0	Washington Nationals over Milwaukee Brewers

Tm	W	L	W-L%	GB
Atlanta Braves	97	65	.599	--
Washington Nationals	93	69	.574	4.0
New York Mets	86	76	.531	11.0
Philadelphia Phillies	81	81	.500	16.0
Miami Marlins	57	105	.352	40.0