The score was tied, but Stacey Mackintosh did not want to play overtime.

The South River senior midfielder knew top-ranked Glenelg had an explosive offense and would be tough to stop in a seven-on-seven sudden death period, so as the returning All-Met got set at the top of the circle for an untimed penalty corner at the end of regulation Monday, she wanted to end the game.

“It added pressure because you know you have to get it in or you’re going to seven-v-seven,” Mackintosh said. “You never want to do that. You want to win it when you can.”

Senior forward Madelyn Santa inserted the corner, and Mackintosh blasted a long shot into the back of the cage with no time on the clock, giving the No. 3 Seahawks a thrilling 3-2 victory over Glenelg in the District V championship game — which matches the Howard and Anne Arundel champions — at Broadneck.

The loss snapped Glenelg’s 31-game winning streak that dated from September 2010, when South River beat the Gladiators in an early-season tournament.

“They’re an awesome matchup,” South River senior goalie Shannon Flanagan said. “It was a great game and I’m glad we got to play them.”

Glenelg (14-1, 11-0 Howard) had outscored its opponents, 128-4, this season and hadn’t trailed all year, but South River (14-1, 10-0 Anne Arundel) came out aggressively and scored twice in the first half to take an early 2-0 lead.

Junior forward Jennie Milligan opened the scoring with 12 minutes 24 seconds left in the first half when she scored among traffic in front of the net after a corner.

Mackintosh made it 2-0 less than four minutes later with a rocket from the top of the circle that mirrored the game-winner, forcing Glenelg Coach Ginger Kincaid to call a timeout.

“It was definitely a shock to our team because we haven’t been in that position,” senior midfielder Mary Kate Olson said. “A lot of people started to freak out and we weren’t playing our game.”

Glenelg settled down after halftime, and sophomore forward Stephanie Asher scored twice in the first eight minutes of the second half to tie the score at 2.

The first goal came after reigning All-Met Player of the Year Alyssa Parker flipped a backhand pass toward the net with 26:02 left in regulation, and the second was on a one-timer off a pass from junior midfielder Emily Russo.

“We just had to calm down because we weren’t used to being down that much,” Asher said. “We just had to get a mind-set where we could imagine the ball hitting the back of the cage.”

Led by Parker, who is a threat to score practically every time she gets the ball, Glenelg had at least four great scoring chances that would have given them the lead, but could never score the go-ahead goal.

The Gladiators dominated play in the second half, but it was Mackintosh who had the final chance and who did not miss.

“We’ve been working on our corners a lot, so we know what she can do,” South River Coach Katie Corcoran said. “When we had the clock stopped and had all that time, I had every confidence that she would hit it in.”