CHATSWORTH — Things couldn’t have started any better for the Flintridge Prep girls’ basketball team on Saturday night.

After that, things spilled out of control with the Rebels facing a lethal defense and equally impressive offense run by powerful Sierra Canyon.

It proved too much for the Rebels to handle, as their season came to a close with a 77-20 road loss to top-seeded Sierra Canyon in a CIF Southern Section Division V-AA semifinal contest.

“You can try to replicate facing that kind of offense in practice, but then you see it in a game situation and it’s probably overwhelming,” said Flintridge Prep first-year co-Coach Kevin Kiyomura, whose fourth-seeded team finished 19-8 after reaching the semifinals for the first time since 2008. “I think we were taken aback a little.

“We were happy to get this far and you could see the growth and maturation throughout the whole season.”

Sierra Canyon (21-9) will meet second-seeded Providence or 11th-seeded Village Christian in the championship game at a day and site to be determined.

Flintridge Prep, which finished second in the Prep League, held a 3-2 lead a minute into the game on a free throw by Maya Okamoto. Sierra Canyon, which last won a CIF title in 2009, then elevated its game on both ends of the court. The Trailblazers used their stifling defensive pressure and transition game to go on a 16-0 run to take an 18-3 lead midway through the first quarter.

Sierra Canyon forced Flintridge Prep into four turnovers in that stretch and had eight fast-break points.

“That’s our philosophy,” said Sierra Canyon first-year Coach Alicia Komaki, who received a game-high 25 points and six blocks from Cheyanne Wallace and 19 points, eight rebounds, six assists and three blocks from Kennedy Burke. “For us, it’s about pressure and then run.

“We have great speed, length and athleticism.”

The Rebels, who were eliminated in the first round of the playoffs the past two seasons, found out firsthand about Sierra Canyon’s ability to swarm defensively and gain full steam toward the basket in transition. Burke gave the Trailblazers a 41-9 lead on a layup with 6:40 left in the second quarter. Sierra Canyon, which entered the contest averaging nearly 80 points per game in the playoffs, held a commanding 53-11 halftime advantage.

Okamoto, who finished with a team-best 10 points, said the Rebels became fatigued trying to stop Sierra Canyon.

“They were the better athletic team,” said Okamoto, who scored all five of Flintridge Prep’s third-quarter points. “I think we just got over our heads and we got a little intimidated.

“I thought we had such a great season and we’ve come a long way as a team. I think we exceeded our expectations just getting here.”

Flintridge Prep, which advanced to the semifinals with a 44-41 quarterfinal home win against fifth-seeded Desert on Wednesday, got a team-high six rebounds from Lacy Coan.

Sierra Canyon got 16 points and seven rebounds from Zoe Goss.