The Tigers, who are ranked for the first time since 2010, improved to 14-1 and ran their winning streak to 10 in a row. Clemson is off to its best start since the 2008-09 season and is 3-0 in the Atlantic Coast Conference for the first time in 11 years.
Reed, a junior guard, hit two crucial 3-pointers late in the game, then shined in overtime with two steals and five points as the Tigers pulled away from a 55-55 deadlock in regulation.
Reed hit 8 of 17 shots from the floor and had a team-high five steals.
Clemson also got 13 points each from guards Gabe DeVoe and Shelton Mitchell and 12 points and 10 rebounds from center Elijah Thomas.
Louisville (11-4, 1-1 ACC) was led by forward Ray Spalding, who had 16 points and 14 rebounds. Forward Deng Adel added 14 points and 11 rebounds while guard Quintin Snider had 13.
Clemson led by as many as six points in the first half before settling for a 23-23 tie at halftime despite shooting just 32.4 percent from the floor and making only 1 of 11 shots from 3-point range.
The Tigers, 9-0 at home this season, used a 17-4 run midway through the second half to pull ahead by eight, but the Cardinals closed with a flourish, outscoring Clemson 15-8 to draw even by the end of regulation.
But Clemson, which connected on only two of its first 17 shots from 3-point range, hit five of its last seven, including two by DeVoe in overtime, to pull away in the extra period.
Clemson, which lost by 32 points at Louisville last season, improved to 2-5 all-time against Louisville.
Tigers coach Brad Brownell has 138 victories at Clemson, tying Oliver Purnell for the third-most wins at the school. Brownell, off to the best 15-game start of his career, will take his team to N.C. State on Thursday, then play host to Miami on Saturday.
--Field Level Media
Louisville | Clemson | |
Ray Spalding 16 | Scoring | Marcquise Reed 24 |
Quentin Snider 5 | Assists | Gabe DeVoe 3 |
Ray Spalding 14 | Rebounds | Donte Grantham 11 |
Deng Adel 4 | Free Throws Made | Shelton Mitchell 8 |
Quentin Snider 2 | Steals | Marcquise Reed 5 |
Ray Spalding 2 | Blocks | Elijah Thomas 5 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
Louisville | 69 | 45.2 | 4-14 | 9-12 | 12 | 42 | 5 | 6 | 21 |
Clemson | 74 | 36.8 | 7-24 | 17-20 | 10 | 34 | 7 | 15 | 11 |