SAN FRANCISCO (Map, News) - Christian Mendieta allowed the Lowell boys’ soccer team about 90 seconds of hope.

But that was all.

The O’Connell midfielder watched as the Cardinals scored a goal in the 67th minute of Thursday’s San Francisco Section semifinal to cut the Boilermakers’ lead to 2-1 and saw as they sprinted back to midfield with the ball, eagerly anticipating an equalizer. But less than 2 minutes later, the slightly built junior controlled a loose ball at the top of the 18-yard box and curled a shot off the far post and into the net, the final conversion in O’Connell’s 3-1 upset win over Lowell at Kezar Stadium. It was the first loss to an Academic Athletic Association foe for the Cardinals (16-3-1), who were 15-0-1 in league play.

The Boilermakers (13-3-1) advance to Saturday’s 1 p.m. final back at Kezar and will look for the first San Francisco Section crown in school history against neighborhood rival Mission (16-8-4).

“We let down there and got overconfident, and it cost us when they got that goal,” Mendieta said. “Since we messed up, we wanted to get one right back and it was a great feeling to see that one go in.”

Mendieta was responsible for getting the momentum on the O’Connell side in the first place, scoring late in the first half to put the Bulldogs on top 1-0. Mendieta, who says he is 5-foot-5 and weighs 126 pounds (O’Connell coach Bob Gamino said it is closer to 5-3 and 90 pounds) took a pass from midfielder Jose M. Nava on the left side of the penalty box, spun and squirmed his way through three defenders and cut the ball with his left foot into the goal. The Boilermakers added to the lead shortly after the intermission as Devyn Martinez sent a high and slow left-footed chip from 20 yards out that was perfectly placed just below the crossbar.

“We still kind of feel like we’re doing a lot of this with smoke and mirrors,” Gamino said. “I have a ton of respect for Lowell and to get past those guys and get to the finals for the second year in a row is as big as it gets.”

Safa Mannah scored the Cardinals’ goal on a loose ball after a corner kick, but Mendieta’s quick response left little opportunity for them to climb back in the game. Lowell had outscored AAA opponents 65-13, but struggled to get going offensively against O’Connell.

“That’s just the way it goes sometimes,” Lowell coach Ernie Feibusch said. “I feel good for Bob and for O’Connell and wish them well. And for us, you just have to hope a tough loss like that is good for the soul.” O’Connell 3, Lowell 1

S.F. Section playoffs

SEMIFINALS

WEDNESDAY: Mission 2, Galileo 0

THURSDAY: O’Connell 3, Lowell 1

CHAMPIONSHIP

SATURDAY: Mission (16-8-4) vs. O’Connell (13-3-1), 1 p.m.

melliser@examiner.com