The Mariners were six outs away.

After seven brilliant innings from starter Roberto Perez, Seattle carried a 3-0 lead into the eighth inning Saturday night at the Peoria Sports Complex, needing just six more outs to advance to the Arizona Complex League Championship Game.

Instead, the Reds scored four runs in a stunning eighth-inning rally, handing the Mariners a heartbreaking 4-3 loss and ending Seattle’s season one game shy of the Arizona Complex League World Series.

For seven innings, the game belonged to Perez.

The right-hander turned in one of the best starts of the season, allowing just one hit over 7.0 scoreless innings while striking out seven and walking only one. Perez kept Cincinnati’s powerful lineup off balance all night, retiring hitter after hitter and giving Seattle every opportunity to move on.

The Mariners finally rewarded him in the fifth inning when Kelvin Alcantara doubled and later scored on Martin Gonzalez’s RBI triple. An inning later, Seattle appeared to seize control as Nick Becker drew a walk before Yorger Bautista launched a two-run homer to right field, stretching the lead to 3-0.

But everything unraveled in the eighth.

With Perez’s night complete, the bullpen couldn’t hold the advantage. Cristian Aray entered and retired the first two hitters before the Reds mounted their rally. After a pair of baserunners reached, pinch-hitter Yael Romero delivered the crushing blow, belting a three-run home run to tie the game. Cincinnati wasn’t finished, adding another run later in the inning to complete a four-run comeback that stunned the home crowd.

Seattle threatened in the ninth, collecting two hits, but the Reds’ bullpen closed the door to send Cincinnati to the championship game.

Despite the loss, the Mariners’ offense produced nine hits. Alcantara led the way with three hits, while Bautista’s sixth-inning homer drove in two runs. Martin Gonzalez added an RBI triple, and Diego Contreras, Leandro Romero, Dalton Davis and Joshua Francis each contributed hits.

The loss ends a memorable season for the ACL West champions, who finished with the second-best record in the Arizona Complex League behind the strength of the league’s top pitching staff. On Saturday, that formula nearly carried Seattle to the championship game.

For seven innings, it looked like it would.

Instead, one difficult inning brought an outstanding season to a heartbreaking end.