The loss was just emblematic of the struggle the Tologs have had all season, Pacella added.
"We've just never seemed to be able to put it all together as a complete team," Pacella said. "It's a shame, we have a lot of talent, but we were never able to get that cohesiveness all season and I think it showed tonight."
The fifth-seeded Mustangs (26-3) had 10 blocks and held a 49-24 rebounding advantage in the game. Channon Fluker and Brandi Dubose each had a game-high 11 rebounds for Muir with Tierra Adams adding 10 more for the Mustangs.
Muir was also balanced on the offensive end with Emoni Jackson scoring a game-high 20 points to go along with eight rebounds. Flynn and Kalyn Richards scored 15 and 14 points, respectively, for the Mustangs.
It was Muir's defense that really made the difference Thursday, but there's still room for improvement, Mustangs Coach Gary Johnson said.
"That's always our key, our pressure defense and get out and go," Johnson said. "We have to do a much better job on the defensive end, though. The next round is going to be much tougher."
The Mustangs got out to a quick 17-2 lead with Jackson scoring 10 of those points. The Tologs notched back-to-back layups from Dana Budzyn and Nora Welsh, who finished with a team-high 12 points and seven rebounds, to trim the deficit to 17-6, but still went into the second down, 22-8.
Muir's offense slowed in the second, but still took a 30-12 lead into halftime after Sacred Heart committed 10 first-half turnovers and got out rebounded, 28-16.
The Mustangs offense got back on track out of the break, scoring 21 points in the third quarter to carry a 51-19 lead into the final quarter.
The Tologs scored a 11 points in the fourth with Budzyn (eight points, three steals) and Ivy Fitzgerald (four points and seven rebounds) both scoring four points in the last eight minutes.
Pacella said Muir set a good a example for his team to follow.
"We're happy to be in the playoffs and it's fun to play a local team," Pacella said, "but hopefully in years to come we can keep building our program to a level of success like John Muir has."