With 20 games remaining in their season, the San Diego Padres look like a strong bet to make the MLB postseason. They have a three-game lead for the National League’s top wild-card playoff spot. And they still have a shot at catching the Los Angeles Dodgers, behind in the NL West by five games.

However, if San Diego ends up missing out on the postseason by one game, Thursday’s 4-3 home loss to the Detroit Tigers might be the game that gets circled as the one that let it get away.

The Padres took a 3-0 lead into the ninth inning. Closer Robert Suarez with his 1.93 ERA, 51 strikeouts in 56 innings and 31 saves took the mound. A series sweep looked comfortably certain, though the middle of the Detroit lineup was batting in the ninth.

Suarez grooved his first pitch down the middle of the strike zone, which Justyn-Henry Malloy lined for a single. Pinch-hitter Jace Jung drew a six-pitch walk after taking the first pitch for a strike. Suarez then got Spencer Torkelson to pop up, giving him an opportunity to get out of the inning unscathed.

Unfortunately, Suarez then walked Colt Keith — again on six pitches, and again after getting ahead with a first-pitch strike. Bases loaded, one out. Uh, oh. Yet Suarez followed up by striking out pinch-hitter Kerry Carpenter with a 101 mph fastball that was outside of the strike zone. Two outs.

All Suarez had to do was get Parker Meadows out to finish the game. Even if he allowed a base hit and a run or two to score, the Padres could still win. The third-year veteran fell behind Meadows with a 3-1 count. Would he walk in a run? Yet Meadows fouled a ball off for strike two. Two outs with two strikes.

Then, with his sixth pitch of the at-bat, Suarez left a fastball out over the plate to Meadows. It was a 101 mph pitch, but the rookie outfielder smacked it to the opposite field and two rows behind the fence for a grand slam and a 4-3 lead.

The Padres still had a chance to tie or win in the bottom of the ninth, facing Tigers reliever Tyler Holton — not regular closer Jason Foley. But Detroit had the ninth inning that the Padres would’ve preferred, getting the first two batters out. San Diego did put the tying run on base with a Xander Bogaerts single, giving NL Rookie of the Year favorite Jackson Merrill an opportunity to boost his award candidacy.

Pitching Merrill low and away, Holton’s slow sweeper got the Padres center fielder to fly out to center to end the game and tag San Diego with what could end up stinging harder by the end of the season. By itself, losing the third game of a series after winning the first two to a .500 Tigers team might not look so bad in the big picture of a season. But in September, with a postseason spot at stake, that’s not a game the Padres can afford to lose.

Overreaction? Perhaps it will look that way in three weeks if the Padres are in the postseason and make a playoff run. But if San Diego barely misses out, that ninth inning could look pivotal. Painfully so.