Mizzou softball couldn’t keep its momentum going Thursday, falling to No. 20 LSU 9-1 in run-rule fashion as the game got away from the Tigers. The loss snapped a five-game winning streak for a Mizzou team still fighting to remain above the .500 threshold required for postseason play.

In the circle for LSU, Jayden Heavener dominated Missouri’s batters in a complete game, holding the Tigers to just five hits while striking out 11 on 28 batters faced.

“Heavener is an All-American pitcher; she’s unbelievable,” Mizzou coach Larissa Anderson said in a news conference after the game. “We got to stay disciplined and lay off that high pitch. She threw it extremely well through the zone.”

LSU started the scoring in the first after Alix Franklin hit an RBI single to leap to a 1-0 lead. Sierra Daniel, who got on base via a walk, rounded third from second on the shallow center field hit to earn the run. In the fourth inning, LSU added one more after Maci Bergeron singled up the middle to score a runner from second base.

The decisive inning arrived in the sixth, as LSU scored seven in an explosive inning. Tori Edwards blasted a two-run homer to deep center field, scoring Franklin, who got on base via an error from Addy Waits. With two outs, Jalia Lassiter added on with an RBI single before Daniel hit a two-run single to extend the lead to 7-0. Kylee Edwards capped the inning with a two-run homer to push the lead to 9-0.

Missouri added one run in response, but it was ultimately not enough to get out of the run-rule. Leading off, Abby Hay walked before Abby Carr hit a single to get the pair on base. An error pushed the two into scoring position before Kayley Lenger walked to load the bases. Freshman Gracie Britton worked a bases-loaded walk to drive in Mizzou’s single run.

Britton, who graduated early from Southern Boone to come to Mizzou, achieved her first career RBI on the walk.

In the circle for Missouri, Cierra Harrison remained steady until the Edwards home run in the sixth, where she would be replaced by Courtney Donahue. Donahue finished the game for the Tigers, allowing four hits and five runs through one inning pitched.

With the loss, Harrison received her first loss since March 8, striking out four while allowing three earned runs, four hits and three walks after five innings pitched.

The Tigers return for game two of the series at 3 p.m. Friday.