But the Scotties rolled off 10 unanswered points and held Pulaski (25-6) scoreless for nearly five minutes as they extended their lead to 47-31.
"It was very, very, very, very, very, very important, et cetera," Mercer junior Erica Lee said. "Coach said you've got to be better by 17 points to win by two, and we needed that stretch to push us ahead."
Lee and Chelsea Goodman each had four points in that span after neither scored in the first half. Lee went on to finish with 12 points and 10 rebounds, and Goodman had seven points, four assists and three steals.
But more important to Mercer's chances, Goodman also all but shut down Pulaski's leading scorer, Tarah Combs.
Combs, who has committed to Morehead State, finished with 10 points. However, she hit a 3-pointer at the buzzer to reach double digits and didn't score from the 5:10 mark of the first quarter until 3:24 remained in the game.
"We challenged Chelsea this week and told her early that she was going to guard her," Souder said. "I told her, 'You're probably going to have to give up points in this game to focus on stopping her. She may get her points, she may get 20.' Chelsea looked at me and said 'Oh, no, she won't.'"
It wasn't Combs who keyed Pulaski Wednesday night. Junior Susanna Todd scored 19 points on five 3-pointers and hit the basket that started the Maroons' run in the fourth quarter.
Pulaski gets within six points in fourth quarter
After Mercer opened up a 14-point lead with 4:12 to play, Todd hit a basket, Combs and Redmond each hit two free throws and Brooke Vinovich scored to get Pulaski within six points at 53-47.
"Being an avid basketball fan, the times I've seen Mercer in their rise to supremacy and how good they are, when they've gotten someone down 15 points, they win that game by 30 or 40 points," Pulaski coach Mike Sowers said. "I'll admit, when I looked up and saw that 15-point lead, I thought, 'Boy, we may have given them all we've got.' But dang if we weren't in it right at the end."
However, Mercer sank five of seven free throws in the final 1:17 to pull out to a 12-point lead before Combs hit a 3 at the buzzer.
Pulaski might not have had to make that late run if it weren't for Courtney Watts in the first half. Watts scored 19 of Mercer's 33 first-half points, including 12 in the second quarter.
Souder said he was told earlier this week that Watts had been named the Kentucky Association of Basketball Coaches' 12th Region girls player of the year. She finished with a game-high 21 points and had four assists, and Souder said he called on her to make a difference in the game.
"I told Courtney before we came out, in front of the team, that his is her team and that she runs it," Souder said. "She didn't get the award just for her name. She deserved it, and it was time to show it. Boy, did she show it tonight. In my opinion, she was the best player on the floor."
"This is the first step, and this is a real important game to get going and start out the tournament," Watts said. "I just wanted to come out and get the job done."
Mercer finished 20 of 52 from the floor for 38.4 percent and won the rebounding battle 33-29. Jillian Horn had eight rebounds and Erin Ashford had nine points and three steals.
Pulaski hit 17 of its 46 shots, a 36.9 percent mark. Victoria Link also reached double figures with 12 points, while Vinovich had 10 rebounds.
"I wish we could have won the district, gotten a better draw and maybe seen Mercer in the final," Sowers said.
"If you're a runner-up in this region, you ain't going to get a good draw. You might as well go out there, play the big boy in the first round, hope you can do your best and just let the chips fall where they may."
PULASKI (25-6) - Susanna Todd 19, Tarah Combs 10, Brooke Vinovich 4, Rachel Redmond 6, Victoria Link 12.
MERCER (23-8) - Chrystal Claunch 5, Courtney Watts 21, Chelsea Goodman 7, Erica Lee 12, Jillian Horn 4, Erin Ashford 9, Krysta Honchel 2.