SEATTLE (AP)—Tom Tolbert scored 18 of his 21 points in the second half and converted two critical three-point plays as No. 2 Arizona defeated No. 7 North Carolina 70-52 Sunday for a berth in the NCAA Final Four.

The victory in the West Regional championship game, Arizona’s 15th straight, put the Wildcats, 35-2, in the national semifinals against No. 4 Oklahoma at Kansas City next Saturday.

It will be Arizona’s first trip to the Final Four but the second for Coach Lute Olson, who took Iowa in 1980. Olson, now one victory short of 300 for his 20-year career, becomes the eighth coach to guide two different teams to the Final Four.

All-American forward Sean Elliott led Arizona with 24 points and teamed with frontcourt mates Tolbert and Anthony Cook in a collapsing 2-3 zone defense to shackle North Carolina All-American forward J.R. Reid.

Reid, a 6-foot-9, 256-pounder who was averaging 18.3 points a game, made only one of four shots in the first half and finished with 10 points. Scott Williams led the Tar Heels with 13.

Arizona, which failed for the first time in the tournament to win by 20 or more points, becomes the first Pacific-10 Conference team in the Final Four since UCLA in 1980 and the first other than UCLA since California in 1959.

North Carolina, which was looking for its 10th trip to the Final Four and eighth under Coach Dean Smith, finished 27-7 after its third regional championship loss in four years.

Arizona trailed 28-26 at halftime, only the second time the Wildcats have been behind at intermission all year, but Elliott and McMillan hit consecutive 3-pointers in the first 2:01 of the second half to revive their sluggish team.