Le Mars (25-12) faced several deficits during the first two sets, only to charge ahead and win both sets 25-20.
The Lady Bulldogs trailed by five points early in the first set, but won six straight points to take an 11-10 lead on a kill by Britney Thompson.
"We were trying to run some different stuff and trying to watch their defense so we could hit around their different blocks," said Le Mars head coach Susan Irwin. "I think we were watching a little bit more than what we were doing on our side. That hurt us a little bit."
Spencer (19-19) led Le Mars 17-16 before the Lady Bulldogs won three straight points to take a two-point lead. A kill by Erin Kommes that deflected off of a Spencer blocker put Le Mars ahead by three points.
"We did a nice job of coming back," Irwin said. "(Spencer) kept us on our toes and we weren't ready for that. That was great competition that we had getting us ready for the next round."
The second set was tied 13-13 before Le Mars began to pull away. Two straight blocks by the Lady 'Dogs made the score 19-15 and drew a timeout by the Tigers. Spencer called another timeout with Le Mars leading 23-18, but the Tigers lost the set four points later.
Spencer outscored Le Mars 15-6 over the next 21 points, but the Lady Bulldogs closed out the final set 25-22.
Carolyn Ahlers hit 11 kills for Le Mars and Morgan Ohm hit 10. Kommes made eight kills and Heidebrink had seven. Thompson hit five kills. Emily Pick made 34 assists in the win.
Ahlers hit one ace on 14-for-14 serving. Kommes and Pick were each 12-for-12 serving with one ace. Ohm served 16-for-17, Thompson was 11-for-12 and Heidebrink was 6-for-7.
Le Mars now moves on the regional final next Tuesday at Humboldt. The Lady Bulldogs must go through No. 1 Charles City (41-1) for a spot in the state tournament. Charles City defeated Webster City 25-23, 25-15, 25-20 on Thursday.
"I think when we've gone down to Thomas Jefferson and played Lewis Central and played at the Heelan tournament that that really helped prepare us," Irwin said. "I think the girls are ready to go and excited to play."