FOREST GROVE — The phrase “March Madness” commonly refers to the college basketball playoffs. It’s clearly an appropriate way to describe high school basketball, too, as demonstrated with a huge upset in the Oregon School Activities Association/U.S. Bank/Les Schwab Tires Class 4A girls basketball state tournament at Forest Grove High School.

Perhaps “Giant Killers” would be a suitable nickname for the Seaside High Seagulls following their surprising 47-42 quarterfinal win Thursday over the No. 1 ranked and undefeated Cascade Cougars (20-1). For No. 8 ranked Seaside (19-4) the win propels them into the semifinals for the first time since 2014.

Seaside, led by coach Mike Hawes, meet the defending state champion Sutherlin Bulldogs (21-5) in a 1:30 p.m. contest Thursday at Forest Grove High. Sutherlin won 42-35 over Mazama (17-7) in Thursday’s quarterfinals to reach the semis. If Seaside wins Friday, it will advance to Saturday’s 6:30 p.m. 4A state championship game for the first time ever.

“I’m extremely proud of all of our kids,” said Hawes. “We knew that if we took care of the ball, then we would have a pretty good chance to win and that’s what we did.”

Led by their the dynamic duo of seniors Maddi Utti (15 points, nine rebounds, six assists) and Sydney Villegas (10 points, 10 rebounds, two steals), the Gulls simply outhustled and outplayed the Cougars to pull out the impressive victory.

“We’re really excited because we came out and played our best to get the win,” said Utti. “We rotated really well in our zone defense and we all did a good job to pull out the win. We’re really, really happy and it’s the biggest win of our career. She (Cascade’s Halle Wright is a big part of their team. We’re excited and ready to play in the Final Four.”

Utti, who injured her chin and right wrist in Seaside’s 38-31 playoff win over Molalla on Saturday, proved capable of overcoming adversity, while helping lead the Gulls to victory. Utti, the Moda Health Player-of-the-Game for Seaside, fired in a jumper from the free-throw line at the outset of the contest, giving Seaside an initial 2-0 first quarter lead.

What followed was a highly physical and very aggressive battle with players elbowing, shoving and pushing each other throughout the contest, as many fell hard to floor often after contact.

Cascade, the Oregon West Conference champions from Turner (near Salem), came back with a 6-2 run to go ahead 8-4. Cascade, led by 6-foot junior Halle Wright (17 points, nine rebounds) remained ahead 12-10 at the end of the first quarter, which included three lead changes. Wright earned the Moda Health Player-of-the-Game for Cascade.

The two evenly matched squads traded baskets early in the second. After Cascade took a 17-16 advantage, Villegas hit a jumper in the post area giving Seaside an 18-17 lead. Utilizing a solid an effective zone defense, the Lady Gulls remained in control, while leading for the remainder of the contest.

“This is so exciting to get a win against the No. 1-ranked team in the state,” Villegas said. “Honestly, I’m kind of surprised we won, because in the last couple of years, we’ve kind of had a tough time in our opening game. I just feel speechless, though right now, but I’m just so very proud of my team.”

Seaside capitalized on a total of 20 Cascade fouls and the Gulls shot 13-for-18 (72.2 percent) from the line to help them extend their lead. Lucy Bodner (four points) hit a jumper underneath giving Seaside a 20-17 edge with 4:03 left in the second. The Gulls sank six free throws in the final 2:43 of the quarter, including three each by Villegas and Utti, who shot 7-for-9 at the line. A Villegas free throw with 8.2 seconds left lifted Seaside in front 26-20 at halftime.

“After the injuries that Utti had on Saturday, she really recovered well and came back strong, and we really needed to have her at full strength,” said Hawes. “We’re extremely proud of the team and everyone made key contributions to helping us get the win. We’re not satisfied with one win, though, because we still have lots of work to do.

Seaside extended the margin to its largest of the game early in the third when Bodner a 10-foot baseline jumper from the side, making it 28-20 with 7:50 on the clock. Cascade, which reached the 2016 finals before losing 45-40 to Sutherlin, responded with a strong comeback effort, trimming it to 38-36 after three.

Cascade got to within 38-37 early in the fourth, forcing a Seaside timeout with 6:06 left. With 4:50 left, Wright fell to the floor hard and was crying and pounding the floor with her fist while obviously in severe pain with a left leg injury. She limped off the court assisted by two assistant coaches.

With Cascade’s best player sidelined, Seaside took advantage of the unfortunate situation though and extended its lead. Seaside sophomore guard Emy Kiser fired in a three-pointer from the corner, putting the Gulls up 41-37 with 3:58 left in the game.

“We had the lead when she (Wright) got hurt, but whenever your top player gets hurt, it obviously affects your team,” said Hawes. “We were in control for most of the game, at that point, so I’m not really sure how much her absence affected the outcome. I’m was incredibly happy to see that she did come back into the game. Wright and Utti are the two best players in Class 4A, so it was a good matchup to see those two players square off head-to-head.”

Cascade trimmed it to 41-39 with 2:37 remaining on two free throws by Karen Miller (12 pts.) but they didn’t get any closer though. Utti’s jumper in the lane made it 43-39 with 2:05 left, but Cascade came back and narrowed it to 43-40. Utti then had a key assist with a long pass from near the top of the 3-point arc to Villegas, whose key basket inside made it 45-40 with 1:30 left.

“I’m really excited to have an opportunity to play Sutherlin, which is a really good team, too,” said Villegas. “I think we’re capable of beating them if we play the same way we did today against Cascade. We just took down the No. 1-ranked team, which really gives us lots of confidence now, and I think we can beat anybody.”

Wright somehow managed to shrug off her injury and then played the final 90 seconds. Cascade trimmed it to 45-42, forcing a Seaside timeout with 44.4 seconds left. Seaside failed to score on its ensuing possession, giving Cascade one final chance. Wright fired up a possible game-tying 3 and missed, but the Cougars retained possession as the ball went out of bounds after being touched by Seaside.

Following a Cascade timeout with 15.1 seconds left, Seaside’s Bryre Babbitt (5 points) grabbed an errant ball after forcing a Cougar turnover and she passed the ball to Utti, who was fouled with 6.7 seconds left. Utti sank both from the line, giving Seaside a 47-42 lead. The Gulls then reacted as expected after a big win with excited players jumping up and down, screaming and hugging one another in a very joyful and emotional victory celebration.