SEATTLE -- The Padres’ chance to separate from the pack in the final weeks of the regular season continues to stop and start.

San Diego lost the capper of its two-game jaunt to Seattle, 5-2 to the Mariners at T-Mobile Park on Wednesday night. The loss, coupled with the D-backs’ 14-4 win over the Rangers, moves San Diego a half-game behind Arizona for the top National League Wild Card spot.

The tiebreaker between the two NL West foes is undecided, and won’t be settled until the Padres’ three-game set at Chase Field to end the regular season. San Diego sits 1 1/2 games ahead of the Mets, who occupy the final playoff position, with another game of breathing room ahead of the Braves.

Fifteen games into an 18-game stretch against teams currently on the outside looking in of their respective playoff hunts, San Diego has gone 8-7. After an off-day Thursday, the Padres will open a three-game set in San Francisco. Following that, three of San Diego’s final four sets are against teams currently sitting in playoff spots.

Seattle’s Bryan Woo retired the first 19 batters he faced before Fernando Tatis Jr. broke up the perfect game bid with a solo home run to left field with one out in the seventh.

The homer was Tatis’ second in as many games, and he punctuated the inning by reaching over the wall in right field to take a homer away from Randy Arozarena.