LA CRESCENTA — Sidney Ortega had plenty on her mind when the ball left her finger tips in the waning seconds of overtime.

The Burroughs High girls' basketball player wasn't sure what the end result would be after taking arguably her biggest shot thus far this season.

Ortega got the positive result she wanted, as she made a game-winning three-pointer with 2.6 seconds remaining in overtime to lift visiting Burroughs to a 49-46 Pacific League victory against Crescenta Valley on Monday.

"At first, I was thinking that I didn't want to see it get blocked," said Ortega, who helped Burroughs improve to 18-6, 10-0 in league and complete a tough two-game season series sweep of Crescenta Valley (17-7, 8-2). "Then I saw the shot go in and I was like, 'Oh, my gosh.'

"It was either make the shot or we go into another overtime. We didn't want to go to another overtime. It's a huge win that we wanted to get."

Crescenta Valley appeared to have things well in hand, building a 40-30 lead on a basket by Alisa Shinn with 5:56 remaining in the fourth quarter. However, Burroughs mounted a furious comeback bid and outscored Crescenta Valley, 12-2, the remainder of regulation to knot it at 42. Burroughs, which rallied to post a 51-49 home win against Crescenta Valley on Jan. 13, then outscored the Falcons by a 7-4 margin in the four-minute overtime session.

Paula Galicia (14 points) of Burroughs, which shared the league championship with Arcadia last season, made a three-pointer with 55 seconds left to knot it at 42.

Burroughs Coach Vicky Oganyan, whose team is ranked seventh in the latest CIF Southern Section Division I-A poll, said the Indians were confident with Ortega shooting.

"We were able to run the base line and we found Sidney in the corner," Oganyan said. "She's a real good shooter.

"It's a great win because we really have some tough kids. They can play especially in crunch time and find a way to win."

The Falcons took a 46-44 lead with 1:05 left in overtime on a pair of free throws by Ella Stepanian, who finished with nine points. Burroughs' Jakarra Waddell then made one of two free throws to pull the Indians to within 46-45 with 58.6 seconds remaining before Brooke Radcliff tied it with a free throw.

Crescenta Valley Coach Jason Perez said the Falcons, who held a 20-14 halftime advantage, couldn't hold off Burroughs.

"We played well for the first three-plus quarters and we have to learn to learn to beat a team we'd been beating most of the game," said Perez, who received 13 points, 12 rebounds and three steals from Shinn and 12 points from Liana Esmaili. "They made a run against us when we had to go to our bench.

"They started to come on late in the third quarter and made some three-pointers. They had a couple of swings and made some shots."

charles.rich@latimes.com