NORWALK — The home opener for the Norwalk boys soccer team turned into a bitter disappointment for the Bears.

Norwalk surrendered three goals in the second half after leading at the intermission and suffered a 3-1 loss to Danbury on Tuesday night at Testa Field in a battle of perennial FCIAC contenders.

The Hatters (2-0) needed less than four minutes to tie the game as Felipe Alves’ blast from the just outside the box caromed into the net after deflecting off the right crossbar with 36:02 to play.

Chris Sari’s rebound goal put Danbury ahead with 11:20 remaining and Ricardo Rodriguez sealed the win by drilling a free kick just inside the left crossbar at the 4:15 mark.

Santiago Mesa took advantage of a misplay by backup Danbury goaltender Felix Escobar to give the Bears a 1-0 lead with 18:02 left in the first half.

“It’s inexcusable,” Norwalk coach Chris Laughton said. “I thought we played pathetic. We showed no fight, no fire. I need a lot of guys to step up, especially our seniors, and they can’t be role players. They have to be leaders on the field.

“We definitely didn’t see that tonight but we’ll learn from it. It’s the only thing you can do.”

Norwalk (1-1) generated little offense in the second half, getting outside 8-0, which gave Danbury an 11-5 edge for the game.

The Hatters attempted six corners — compared to just one for Norwalk — and almost scored again in the final minute, but Bears’ goaltender Tyler Dalton stopped Alves on a breakaway.

Dalton, one of the FCIAC’s top netminders, was the lone bright spot for the Bears with nine saves.

Danbury nearly scored in the first 20 seconds of the second half on a long run by Justin Warren, who held on to the ball too long, allowing Dalton to cover up, but it was a harbinger of things to come for the Bears.

“I thought we played incredibly well in the first half,” Danbury coach Sean Colley said. “We just had the mishap with the backup in the goal area and we responded to that really well.

“Then in the second half, we came out fired up. I think that goal in the first five minutes took a lot of pressure off because now it’s an even game. You go out and play and if you tie, you tie a top 10 team at home. You live with that.”

Danbury entered the game ranked fifth in the coaches’ Class LL-L state poll while Norwalk was sixth.

“The way we played tonight, there’s no reason for us to be in the top 10 poll, and that’s just being honest,” Laughton said. “We have to show up ready to play every night. These guys know the routine. They know the expectations to be part of this program and they didn’t fulfill that tonight.”

On Norwalk’s goal, Escobar, who was making only his second career start after all-state goaltender Ian Shannon suffering a torn ACL two weeks ago, mishandled a free kick.

Chrisian Moncada pounced on the loose ball and his initial shot was stopped by Escobar.

Mesa banged in the rebound for his fourth goal in two games after scoring a hat trick in Norwalk’s season-opening 7-0 win over Trinity Catholic.

The Bears, however, could not build off the fortunate goal.

“We were able to sub frequently all game,” Colley said. “We kept fresh legs on them, we pressed them. We didn’t allow then any possession, which I thought was key. We had the ball for the majority of the game.”

Danbury’s second goal was the result of a strong buildup on the left side by Sari and Kevin Krohomer.

After Dalton came far out of the goal to make a save on Krohomer’s shot, Sari followed up the rebound to give the Hatters a 2-1 lead.

Escobar finished with three saves, all in the first half.

Norwalk has a short turnaround as the Bears are back in action on Thursday when they visit Stamford (4 p.m.).