The Riverdale girls weathered a late charge by Blackman on Friday night to win their 43rd straight 55-42 in a matchup of nationally ranked teams.
MTSU signee Tyisha Petty of Riverdale drained 6-of-6 free throws in the final 40.3 seconds to give Blackman its first loss.
Riverdale (20-0, 5-0 7-AAA) is ranked fifth nationally by USA TODAY and second by ESPN Hoopgurlz and MaxPreps. Blackman (18-1, 3-1) is ranked ninth by MaxPreps.
Riverdale is No. 1 and Blackman is No. 2 in the state Class AAA poll and The Tennessean Midstate top 10.
Blackman had trimmed a 21-point third-quarter lead to 49-40 with 1:03 left before Petty iced the game.
"I knew that I was the one that was going to have the ball, since I'm the point guard," said Petty, who finished with a game-high 19 points. "I had to step up and knock them down."
Riverdale is the lone unbeaten district team left at the midpoint of the conference season. Blackman's gym, which seats 2,200, was near capacity. And fans watching from the doorway throughout the contest.
"The crowd was unbelievable," Riverdale coach Cory Barrett said. "You wish every night could be like that as far as the crowd. Everybody from Murfreesboro and surrounding areas, we appreciate you coming. And I'm sure Blackman does with their ticket sales."
MTSU signee Olivia Jones' second of back-to-back 3-pointers started a Riverdale 12-0 run to give the Lady Warriors control in the first half. Riverdale led 25-9 with 4:28 left in the first half after Alexa Middleton's rebound bucket.
"I think our experience helped in that run," Barrett said. "Then, their comeback was simply because they are so talented. They have a great team."
Blackman finished the game 23 percent from the field on 13-of-57 shooting, but hit 15-of-17 from the free throw line.
"We shot the ball poorly," Blackman coach Chad Hibdon said. "It's because they speed you up. I think for a lot of our girls, we've talked about it, we've shown them on film other girls rushing their shots, but really until you get out there and get your feet wet with the young team we have it's that learning experience."
Blackman ended the third quarter with a 9-0 run to trim Riverdale's lead to 43-31. Petty pushed the lead to 49-35 with 3:43 left on a layup with defender Micah Norris on her hip. That marked Riverdale's final field goal of the game.
Jones had 14, and Middleton finished with 13.
Freshman point guard Crystal Dangerfield and Alex Johnson led Blackman with 12 each.