Hugo Reyes’ breakaway goal in the second half and a disciplined defensive effort propelled Sierra to a 1-0 win over rival East Union on Tuesday at rain-soaked Daniel Teicheira Memorial Stadium.

It’s an important early result for the host Timberwolves (3-0-1, 7-4-3 overall), who knocked East Union (3-1-0, 11-8-1) from the top of the Valley Oak League standings while keeping pace with Kimball (3-0-1, 8-1-1).

East Union and Kimball are the defending co-champions.

“I think we stepped it up,” Sierra coach Joe Pires said. “There have been games where we don’t step up in big moments for different reasons. There have been times when the better team didn’t win … today, we may not have been the better team, but we were the bigger team. We played with bigger heart.”

He credited the midfield triumvirate Diego Lopez, Emmanuel Ruiz and Alejandro Sanchez for setting the tone.

“That’s the heart of the team,” Pires added.

It was a deflection by Sanchez that kicked off the decisive goal. He intercepted a pass from the East Union backline in the middle of the pitch, knocking it ahead to Reyes on the first touch. Lancers defenders Luis Mata and Adrian Vivanco did well to recover, but Sierra’s speedy striker was still able to cut toward the middle of the box and place a right-footed shot past goalie Andres Garcia (four saves).

The T’wolves missed similar opportunities throughout, and Reyes could have had a second-half hat trick with some of the looks he had.

“We’ve been missing a lot of those shots,” Reyes said. “We have to keep practicing those.”

For now, Sierra will relish in this needed boost of confidence.

“Now we know we’re one of the biggest teams to beat,” Reyes said.

The Sierra defense has been leaky at times this season but managed to shackle one of the top goal scorers in the Sac-Joaquin Section for its second clean sheet. East Union forward Giovanni Perez, who recently scored his 100th career goal, was held without a shot in the first half and had two long-range attempts go wide.

The Lancers were blanked after outscoring their first three league opponents, 19-1.

“We knew East Union had great attackers, they’re a great team,” Sierra center back Christopher Stackpole said. “We know we have very good defenders and I was very comfortable in our back line.

“Our game plan was just to be (cautious), keep them in front and don’t stab. We did that all day and it was great. Held them to zero goals — a shutout. Great game for us.”

Although they were nearly even on shot attempts — East Union had the 12-10 edge — it was Sierra that had the better chances. The Lancers’ best opportunities came in the final 10 minutes, but Alexis Berber and Cesar Reynoso were off the mark on their half-volleys on second balls.

“We came out flat,” East Union coach Ronnie Green said. “We didn’t show any intensity until they put one on us. I think we came in too timid, even though we played at Sierra and came in knowing what it meant. It was still a good game by both teams, so I’m OK with it.”