The Sioux City North Stars played their best at just the right time.

North used a big fourth quarter to erase a 10-point deficit and beat West Des Moines Valley 55-51 in the Class 4A semifinals.

That sends the top-ranked Stars (23-2) into a title game showdown on Saturday night with No. 2 Des Moines Roosevelt, the defending state champion. Roosevelt advanced with a 61-53 victory over Cedar Rapids Washington.

Fifth-ranked Valley dominated early behind center Molly McClelland, who scored 18 first-half points on 8-for-10 shooting. The Tigers led by as many as 14 points in the second quarter and were up 27-15 at halftime.

The Tigers' lead was 41-31 late in the third quarter when North began its rally.

Sarah Jane Bowden sank a free throw for the Stars, starting a 12-0 run that continued into the fourth quarter and put them up 44-41. They led the rest of the way.

Valley drew to 46-45 on McClelland's bucket inside, but North made seven of its next eight free throws to secure the victory. The Stars ended up outscoring Valley 23-10 in the fourth quarter.

Jacqui Kalin led North with 25 points, 21 in the second half. A Northern Iowa recruit, Kalin scored 12 points in the fourth quarter and hit Tanaeya Worden cutting to the basket with a perfect bounce pass for a layup that gave North a 46-43 lead.

Worden finished with 16 points.

McClelland wound up with 23 points to lead Valley (20-5). The Stars did a good job cutting off passes to her in the second half and limited her to three shots over the final two quarters.

Erin Johnson scored eight for the Tigers.

North is seeking its first state championship. The Stars lost in the first round in each of their two previous state tournament trips.