Sierra and Lathrop met for a marquee non-league match Friday to tune up for their respective first-place matches to come.

For the second time this week, visiting Sierra had to shake off a lackluster start, this time holding off the Spartans, 14-25, 25-22, 25-15, 25-22.

Setter Primo Estandarte led the Timberwolves attack with six kills, two aces and 28 assists. He

also had four block assists. Middle blocker Owen Altadonna netted 14 kills and five blocks, outside hitter Santino Flores added 10 kills and libero Bonpatrick Estrella collected 10 digs, nine service points and three aces.

Gabriel Fa’ali’i had 10 kills and three aces for Lathrop (8-3). Alexander Vere set 16 assists, Charles Reyes racked up 21 digs and Marco Palomares produced four kills, 15 service points, two blocks and five digs.

On Monday, Sierra (11-3) opened Valley Oak League play against East Union and came back to win in five sets after dropping the first two.

Coach Danielle Deerinck hopes her team can build off the experiences and be ready for its big league showdown with Manteca next Wednesday. The two rivals are co-leaders and reigning co-champions. The Timberwolves are ranked ninth in the Sac-Joaquin Section, according to MaxPreps, while Manteca is No. 12.

“I just said to them, ‘When did we turn into this slow-starting team?’ It has definitely been a pattern and we have to work through that,” Deerinck said. “I think these slow starts, as much as we don’t want to do it, I think it’s good because those are the biggest tests. Even when games are not starting in our favor, you learn to not give up and understand we have to use each set as a new opportunity to start out stronger.”

Sierra struggled with missed serves and serve receive in the opening set, ending with four service errors (16 for the match) while giving up six aces.

Altadonna and the Timberwolves got untracked in game 2, as Estandarte looked to get his 6-foot-5 middle more involved in the offense. He was also a factor in defense, combining with Rumir Bioc to stuff a Fa’ali’i block and stretch Sierra’s lead to 17-10.

Lathrop battled back to tie it at 21-21 on an ace from Reyes, but the T’wolves regained control and secured the set with a kill from Altadonna.

“At one point, I them we’re playing chess right now, we have to play smarter,” Deerinck said. “Yeah, we can hit it hard, but on some of the off-set ones, even though we were doing it by accident at first, they were working. Mix it up, roll shots — it doesn’t have to be a power hit every time.

“I feel like by the end of the first set we made those adjustments to come back a little bit and create that momentum for the second set. Going forward, they just had good energy.”

The third set started out competitive, but the Spartans were eventually buried by their own mistakes. Yatharth Katyal and Altadonna had long service runs to help close out the third set, as Sierra ended on a 13-1 flurry after trailing 14-12.

“That’s been the focus of our team this whole year, is to try and stay consistent,” Lathrop coach Toa Fa’ali’i said. “Today, in the first set, we came out really good but then just fell flat to start the second set.

“We were trying to counter what Sierra has, they have some really good players. We tried to kind of push the tempo, but it didn’t go in our favor. It was error after error, but I don’t want to take away from Sierra because they’re a great team with a great coach. That’s what good teams do; they weather the storm. You lose the first set but keep yourself composed. I have to give credit to them.”

It only got worse for the Spartans when lost their setter early in the fourth game. Vere took an inadvertent elbow to his head when Estandarte scored with a dink to give the T’wolves the 10-9 edge.

Lathrop, to its credit, continued to compete and even had some good moments with back-up setter Sayed Anam, who executed a perfect back set put away by Palomares. That tied it at 14-14.

A five-point service run from Jonvic Paredes helped create separation for Sierra.

“It was a tough loss, but we have to have that next-guy-up mentality,” coach Fa’ali’i said. “When somebody goes down, the next person has to step in, and (Anam) didn’t do too bad.”

Lathrop’s busy week is not over yet. After playing its third match in four nights, the Spartans are competing in the Stockton Classic today.

They’ll then head to Weston Ranch, the No. 2-ranked team in the SJS, on Monday for a non-league rematch before returning to Western Athletic Conference action on Tuesday when defending champion Mountain House visits.

“This was a good match for us, because I know Mountain House has a good middle, too,” Fa’ali’i said. “Playing against Owen, I felt like it would help us get ready for Mountain House. Sierra plays fast, and that helps us get ready for what’s coming.”