Down seasons just do not exist at Mountain View.

The Cougars knocked off two-time defending state champion Corvallis, 62-51, on Friday in a first-round state playoff contest at Mountain View. And now the Cougars are headed back to the Class 5A boys basketball championship tournament in Eugene despite having to replace 10 seniors from last year’s squad that placed fourth at state.

Cougar junior Grant Lannin had the game of his career. The 6-foot-4-inch wing scored a game-high 18 points — all of which came in the second half — in addition to recording 11 rebounds, three assists, three blocks and two steals. With Lannin exploding after the break, Mountain View rallied back from a 25-21 halftime deficit to advance to the 5A state tourney for the sixth time in seven years.

The Cougars (21-3 overall) will face Wilsonville (18-8), which upset Redmond 59-47 on the road Friday, at 3:15 p.m. on Wednesday at the University of Oregon’s Matthew Knight Arena.

“People don’t understand how hard it is to get back to Matt Court,” Mountain View coach Craig Reid said. “We’ve had so much success here in football and basketball, and sometimes I think people take that for granted.”

Cougar senior wing Mitch Modin added 16 points, two dunks and four steals, sophomore point guard Ments Haugen contributed eight points and three assists while playing a team-high 30 minutes, 45 seconds and senior forward Erik Siefken recorded five points and eight rebounds. Mountain View, which rolls into the state tournament on a nine-game winning streak, made 16 of its 21 shots in the second half (76.2 percent) after going just seven of 20 from the field before halftime.

“They put us in foul trouble, that created some matchup problems,” Corvallis coach Greg Garrison said. “Give them (the Cougars) credit. They played harder in the second half than we did.”

After trailing all of the second quarter, Mountain View opened the third quarter on a 13-7 run, eventually grabbing a 34-32 lead with 2:50 left in the period. Entering the fourth quarter, the Cougars led 41-34, at which point Lannin took over. Averaging 11.9 points per game this season, Lannin had 15 points in the final period against the Spartans (15-10), including seven points during a pivotal 1½-minute stretch in which Mountain View turned a 46-42 lead into a 55-42 advantage.

“He stepped up when we needed it most,” Reid said about Lannin. “That’s what (big-time) players do.

“He’s got great capabilities,” Reid added. “But he’s still mentally maturing. We forget that because he’s a big, strong kid.”

Marion Clark came off the bench to lead the Spartans with 16 points. Dylan Duvall added 13 points for Corvallis, which had won six of its past eight games before Friday. The Spartans shot just 34.6 percent from the field against the Cougars (18 of 52), though, and were outrebounded 33-19.

“It feels so good going back to state,” Lannin said. “People thought this would be a rebuilding year for us with just three seniors (with varsity experience) back. But we played as hard as we could and we’re headed to state.”