UH improved to 15-8 all-time against the Pirates (36-28).
Wagner's 19th home run of the season gave UH a 2-0 lead in the third inning. It was a two-run shot over left field, scoring freshman Jennifer Klinkert, who had walked. Wagner, who set the UH single-season mark in Thursday's 9-1 win over Memphis, now holds the C-USA single-season record as well.
Wagner also moved into fourth place on the UH career charts and ninth in the C-USA annals with 24 career round-trippers. Her next home run will move her up a spot on both career lists.
Shamblin continued the long-ball trend later in the inning, hitting a two-run home run over left field, scoring junior Haley Valis, who reached base on a walk. The home run was Shamblin's third this season.
ECU responded in the bottom of the inning, when Erin St. Ledger hit a solo home run to right center.
The Cougars extended their lead on back-to-back doubles from freshman Baillie Lott and junior Christa Raley in the sixth inning. After Lott reached base, Raley brought her home to give UH a 5-1 lead.
Shamblin got out of a jam in the bottom of the seventh. The Pirates loaded the bases but Shamblin was able to get ECU's Vanessa Moreno to fly out to deep center field to end the game.
Shamblin (32-3) eclipsed her own UH record for single-season wins with the victory. She went the distance, allowing one run on two hits while striking out five. She has won her last 23 games. Her last loss came on March 18 against Virginia Tech.
Houston will play No. 2 Central Florida in the championship game on Saturday. First pitch is scheduled for 1:36pm. UH split two games with the Knights during the regular season. Houston is 1-1 in C-USA championship games.
Fans can follow Saturday's final on Gametracker by clicking on the softball schedule page at http://uhcougars.cstv.com/.