In high school basketball, as in much of life, perfection can be elusive.

Sometimes you meet a more talented opponent. Sometimes the ball doesn’t go in the basket. Sometimes, you just have a bad night.

But that’s the funny thing about the Shawnee Mission South boys team this season. The Raiders have had a few bad nights … but their defense never really has.

It was that defense — relentless and pressurized — that allowed SM South to take down rival Shawnee Mission East 65-47 in a heated matchup that served as the de facto Sunflower League title game.

“Defense,” SM South coach Brett McFall said. “We take a ton of pride in our defense.”

The Raiders, who improved to 20-0 and 11-0 in the Sunflower League, continued their storybook year with their second Sunflower League title in four years and first perfect regular season since 1990, when Greg Gurley led the Raiders to their only state title before he headed off to play at Kansas. The last SM South league title squad was led by current K-State guard Will Spradling.

This time, it was a true ensemble performance. A perfect one — so far.

“You gotta take it one game at a time,” said SM South senior center Josh Pedersen, who finished with 16 points. “I think we did a really good job of just focusing on the next game. But now that we’re here, we’re not done.”

SM East dropped to 18-2 and 10-1 with its first loss against a Kansas City-area team. The Lancers will enter the postseason as the No. 2 seed in their Class 6A substate behind top seed Blue Valley Northwest. But they will avoid BV Northwest — and SM South, which dropped to Class 5A this year — in their four-team tourney to go to state. SM South, meanwhile, will be the heavy favorite to win the Class 5A title.

But when the night began, substate pairings and postseason draws hardly mattered inside the packed and noisy SM East gymnasium. As the local fire codes kept fans waiting outside, McFall was still concerned whether his guard-heavy squad could match up with SM East’s long frontcourt.

SM East would start the game in a triangle-and-two look, an early attempt to combat the Raiders’ quickness advantage. And the Lancers did have a distinct size advantage, with senior Zach Schneider, 6-foot-7, and sophomore Lucas Jones, 6-foot-6, towering over SM South’s smaller lineup.

But SM South, led by sophomore Dainan Swoope and Pedersen, opened the game with a barrage of three-pointers, pulling SM East into a man-to-man defense. SM South junior guard Devin Newsome controlled the tempo, and the Raiders took a 37-26 halftime lead.

“He’s the best defender I’ve seen in a long time,” McFall said of Newsome. “He doesn’t get tired. He doesn’t stop. And then he runs the team.”

SM East, which got 15 points from Schneider, cut the lead to 47-40 on a second-half bucket from Jones. But South went on a 15-4 run and put the game away.

“We wanted to turn it into a full-court game,” McFall said. “We knew we were quicker; we knew we were more athletic. We knew there was no way they could guard us man.

“And once we hit shots, they had to play man.”