McClymonds got a runner in the lane from Gabby Gaines at the 5:36 mark of the second quarter to get within two, 22-20. The margin was still tight at five, 27-22 when Warriors post Da Ja Nay Powell dropped in a layup with 4:26 remaining in the first half, but it got ugly from there.
Reed (3-1) closed the second period on a 12-2 spurt and extended its edge to 15 by halftime, 39-24.
"We started getting in the right spots. Our defense got going and that improved our tempo," Reed coach Sara Ramirez said.
The two teams traded buckets in the third period as McClymonds (4-6) outscored Reed in the eight-minute stretch 18-16, leaving the scoreboard to read 55-42 heading to the final quarter.
Reed dominated play in the final period, outscoring McClymonds 25-8 in the last eight minute to account for the 30-point margin.
"We just woke up," Reed senior Gabby Williams said of the Raiders' improved play as the game wore on. "We'd been being lazy all day. It was the day after Christmas. We probably weren't as focused as we need to be. We learned our lesson. We won't let that happen again tomorrow."
Raiders shooting guard Tyler Sumpter drained a trey with 7 seconds remaining on the clock. It proved to be the final points of the tournament tilt. The 30-point gap was Reed's biggest lead of the matchup.
Sumpter finished 23 points and dropped five 3-point bombs in the romp. Williams, Reed's senior point guard, poured in a game-high 26 points.
Thursday's tournament game was only the third game back for Williams, a UConn recruit, who is just returning after sitting out the better part of a year with a torn ACL.
"She looks like she hasn't taken any time off," Ramirez said. "Every game back she starts getting a little bit better. She's harder on herself than anyone. That's the kind of player she is. The more she plays, the fewer mistakes she'll make. She's going to find her rhythm and when she does, she's pretty much unstoppable."
Powell led McClymonds, posting 16 points in defeat. Angela Lee chipped 15 points and Gaines added 10 to the Warriors' losing cause.
"The biggest thing was I thought we started watching and got complacent," veteran McClymonds coach Dennis Flannery said. "For the first 12 minutes, we were cutting through lanes and playing help defense. And then we started watching ... Reed is an outstanding team. They beat us 10 out of 10 times with where we're at right now, but we still did too much watching."
Reed plays California schools Weston Ranch of Stockton and Palo Alto Friday. Game times are 10:30 a.m. and 4:30 p.m.
*Earlier at McQueen Thursday, Spanish Springs got off to a good start and coasted to a 51-41 tournament win over Truckee.
Spanish Springs put together one of its best offensive quarters of the early season in the first period against Truckee. The Cougars' full-court pressure paid dividends early, helping the local squad to run out to a 21-10 lead after the initial period and it played from ahead the rest of the way.
Despite a 21-point first quarter and a quick double-digit lead, Spanish Springs could not really pull away. The Cougars led at the half 32-19. They led after three quarters 42-30 and held on for the 10-point victory.
"We put a little pressure on them got a few steals and layups in the first quarter," Cougars rookie coach Art Cardenas said. "They adjusted and we got out of it. Then we went more to straight man-to-man.
"Overall, the defense was all right, but it could've been better. We had some breakdowns, a little poor communication at times where we were unsure who we had and left shooters open."
Cougars all-league point guard Hannah Woytek scored a team-high 13 points for Spanish Springs while teammates Mariah Vargas and Katrina Prendergast added 11 and 10 points respectively.
The Cougars will get in a pair of games Friday in McQueen's three-day tournament as they face Yerington at noon and Lowry at 4:30 p.m.