On September 13, the Padres won their 31st game of the season, ensuring that they would finish with a winning record for the first time since 2010. On September 20, the Padres beat the Seattle Mariners 4–1 to clinch their first postseason appearance since 2006. They defeated the St. Louis Cardinals in the 2020 National League Wild Card Series. The Padres won their first postseason series since the 1998 NLCS. Game 2 of their NL Wild Card Series was also the first home postseason win since Petco Park opened and since Game 4 of the aforementioned 1998 NLCS. The Padres winning Game 3 of the NL Wild Card Series also clinched their first postseason series at home since Game 5 of the 1984 NLCS (also a winner-take-all game). The Padres were defeated by their NL West rival Los Angeles Dodgers in the 2020 National League Division Series at Globe Life Field.