Cauley-Stein, a 7-foot freshman manning the post for Kentucky (18-8, 9-4 Southeastern Conference) with Noel sidelined, blocked attempts by Kyle Fuller and Kedren Johnson 9 seconds apart before grabbing Johnson's missed 3-pointer with 17 seconds left and drawing a foul.
Cauley-Stein made 1 of 2 free throws for 74-67 lead that offset Sheldon Moats' 3 for Vanderbilt (10-15, 4-9) with 3 seconds remaining. Cauley-Stein finished 8 of 10 from the field and grabbed seven rebounds to provide Kentucky a sorely-needed victory after the Wildcats were shellacked 88-58 Saturday at Tennessee in their first game since Noel sustained a season-ending left knee injury at Florida on Feb. 12.
Noel's first public appearance since tearing his anterior cruciate ligament boosted the morale of the Wildcats, who had to withstand another Commodores rally.
Trailing 51-41 with 14:46 remaining, Vanderbilt's 18-10 run over the next 10-plus minutes got the Commodores within 61-59. Julius Mays answered with a 3-pointer to give Kentucky a five-point lead before Cauley-Stein added a basket leading up to his defensive heroics.
Archie Goodwin added 16 points and Ryan Harrow 12 for the Wildcats.
Johnson had 17 points and Rod Odum 16 for Vanderbilt.
Fuller added 14 and Henderson 13 for Commodores, who made 10 of 22 (45.5 percent) from beyond the arc. That still wasn't enough to overcome the Wildcats, who shot 29 of 56 overall and outscored Vanderbilt 38-24 in the paint.
Kentucky faced huge pressure to win for many reasons, mostly to atone for its embarrassing 88-58 loss to Tennessee, its first game without Noel. The general ugliness of that outing resulted in Calipari questioning the coachability of a couple of unnamed Wildcats before backtracking earlier this week.
Then there's the matter of Kentucky's postseason prospects, which were shaky before Noel's injury. Losing him and then the first contest badly without him created urgency to regroup, especially with Big Blue Nation becoming nervous.
Many hurdles remain for Kentucky before next month's SEC tournament, but this game showed the Wildcats' pride and composure. They didn't force shots and involved everybody on offense, and there were several times on defense that teammates battled for loose balls.
Most important, the Wildcats didn't give the Commodores an opening like the last meeting in Nashville on Jan. 10. Noel's controversial late basket helped Kentucky overcome blowing a 16-point lead and escape with a 60-58 win, and it demonstrated the luxury of having two big men.
He and Cauley-Stein combined for seven blocks that night, leaving Vanderbilt to try and offset things from the outside. Noel's injury eight days ago changed everything about Kentucky and especially inside, where 7-footer Cauley-Stein must provide the presence.
Facing a huge obstacle in Cauley-Stein, but nothing like the 6-10 Noel, Vanderbilt saw opportunities for a different outcome, especially after outrebounding the Wildcats 42-37 the first time around.
Kentucky wasn't having it, spotting Vanderbilt a 6-4 lead before taking control with efficiency that provided a 42-34 halftime lead. A 21-7 run over 8 minutes, 6 seconds sparked the Wildcats to a 25-13 lead and 19-of-31 shooting (61 percent) helped offset Odom's 4-of-4 shooting from 3-point range.
The Wildcats' guard play also improved as Goodwin, Harrow and Mays combined for 10 assists with just one of Kentucky's three first-half turnovers. Cauley-Stein and Goodwin each scored 12 while Harrow added 10 as Kentucky outscored Vanderbilt 24-8 inside.
Besides his offensive re-emerging after two scoreless efforts, Harrow showed emotion and hustle. He yelled after driving for a layup and foul, then rebounded his missed free throw and fed Kyle Wiltjer for a 3-pointer and 42-30 lead.