Clinging to a 2-0 lead after five complete innings, Notre Dame appeared ready to cruise to its third SEMO Conference tournament title.

But Poplar Bluff had aspirations of its own in mind.

The second-seeded Mules tallied all of their runs in the final two innings and held on to win the SEMO Conference tournament championship with a 4-2 victory over the top-seeded Bulldogs on Monday at Capaha Field.

"We lost focus. That's the thing. You've got to smell to kill and go with it, and we just didn't take advantage of it," Notre Dame coach Jeff Graviett said. "We had a 2-0 lead. That should have been enough. You've got to give Poplar Bluff credit for taking it away from us."

The win marked the first SEMO Conference tournament championship in the history of the Mules' program.

Poplar Bluff players run out to celebrate with relief pitcher Jared Moses after defeating Notre Dame 4-2 in the championship game of the SEMO Conference Tournament Monday, May 4, 2015 at Capaha Field. (Fred Lynch)

"I'm still a little speechless after that one," Poplar Bluff coach Steven Edwards said. "That was an obvious great opponent -- No. 1 in the state in their class and a pitcher going to Mizzou. Being down two [runs], the guys answered -- pulling from the same end of the rope like we've been talking about, doing the little things, being unselfish, putting the bunt down when we have to put a bunt down, being a team."

The loss snaps a 17-game winning streak for Notre Dame, which entered the game as the top-ranked team in Class 4.

Bulldogs starting pitcher Graham Ruopp and Poplar Bluff starter Kameron Misner were locked in a scoreless duel until Notre Dame (19-4) took a 1-0 lead in the bottom of the fourth.

Dean Crippen reached base on an error before Thomas Himmelberg sent a one-out single into left field. After Hunter Eftink reached on a walk to load the bases with two down, Ross Essner struck out but reached on a passed ball that scored Crippen to plate the game's first run.

The Bulldogs added to their lead in the bottom of the fifth, when Chase Urhahn led off with a single to right field. Urhahn stole second and third to set up Dean Crippen, who blasted a one-out single into left field to score Urhahn and push Notre Dame's lead to 2-0.

"He's been doing it all year for us," Graviett said about Crippen. "We expect him to. He's been solid for us when we get in those situations."

Notre Dame starter Graham Ruopp pitches to a Poplar Bluff batter during the first inning of the SEMO Conference Tournament Monday, May 4, 2015 at Capaha Field. (Fred Lynch)

But then came the sixth.

Poplar Bluff (16-5) took advantage when a one-out error at shortstop allowed Kameron Misner to reach base, and Brandon Stuckenschneider scored Misner on a double into left field. Ruopp struck out the next batter, Joe Darlin, but a passed ball mandated a force out at first while Stuckenschneider rounded third and headed home. The rushed throw from first escaped the glove of the catcher as Stuckenschneider safely slid across home plate to tie the game at 2-all.

"We had him 0-2. It really looked like Graham had him where he wanted him," Graviett said about Stuckenschneider's at-bat. "He found a way to just put the bat on the ball, and it found a spot out there in left field to give them a little bit of momentum.

"We just never really recovered from that. We had a couple opportunities our self. The difference was they got big hits when they needed to, and we didn't."

Despite a hit batter and a walk, Ruopp struck out Dalton Cooper to secure the final out, but the damage was done.

"He was just trying to get in there and kind of feel for himself out there," Graviett said about Ruopp. "The gameplan was to get him six [innings], and we were going to finish with Hunter Eftink. But we got greedy there and tried to get one more inning out of him. *... I thought he battled through there."

The Bulldogs were held scoreless in the bottom half of the sixth, and Poplar Bluff took the lead for good in the top of the seventh.

Kirby Coleman, the Mules' No. 8 batter, reached base after getting hit by a pitch, and a bunt single by Tyson Cox put runners on first and second with nobody out. Jared Moses blasted a hard-hit grounder right back to Ruopp. The ball ricocheted off Ruopp's foot and loaded the bases.

Notre Dame's Chase Urhahn steals third base as Poplar Bluff's Dalton Cooper covers on the play during the fifth inning of the SEMO Conference Tournament Monday, May 4, 2015 at Capaha Field. (Fred Lynch)

Ruopp was able to force Misner to fly out to left field, but Stuckenschneider followed with a two-run single into right field, giving Poplar Bluff a 4-2 advantage.

Ruopp was replaced by Eftink, who struck out the next two batters to retire the side.

The Bulldogs' starting right-handed pitcher went 6 1/3 innings, struck out seven, walked one and gave up seven hits and four runs (two earned) in the losing effort.

Ruopp stayed ahead in most of his pitch counts early on, and Graviett said he liked what he saw from his starter.

"He just comes right at you. I don't think that's any secret," Graviett said. "Most of these teams have figured that out. He's going to come right at you and dare you to hit it.

"We tell him all the time that we want something done in three or four pitches and to keep pitch counts down. He really takes to that. He gets a lot of strikeouts, but that's not really what he's going in for. He's trying to get the weak groundball and trying to let our defense work."

Misner walked Logan Heisserer and gave up a single to Crippen to begin the seventh before being replaced by Jared Moses, who forced three quick outs to earn the save and send the Mules home in celebration.

Misner pitched six innings to pick up the win on the mound. He had eight strikeouts and three walks and gave up six hits and two runs -- one earned.

"He did a tremendous job, not only with his bat but on the mound," Graviett said about Misner. "*... I feel like we're a pretty quality hitting club, and he kept us in check and made some huge pitches when he needed to."

With the postseason less than two weeks away, Graviett said he hopes his players use the loss as a valuable learning experience.

"We didn't expect to win all these games. We kind of get our hearts set on this conference tournament, but we've got to play again tomorrow," Graviett said. "Right now, the bigger picture is the postseason, the district, the final four, so we've got to learn from what we did today and get right back at it tomorrow."

Poplar Bluff 000 002 2 -- 4 6 2

Notre Dame 000 110 0 -- 2 7 2

WP -- Kameron Misner. LP -- Graham Ruopp. 2B -- Brandon Stuckenschneider (PB), Joe Darlin (PB). Multiple hits -- Poplar Bluff: Stuckenschneider 2-4; Notre Dame: Chase Urhahn 2-4, Dean Crippen 2-4.