Marquette (20-4, 9-2) led by 15 early in the second half. The Golden Eagles took a 66-63 lead on two free throws by Howard with 53 seconds left, but Phil Booth answered with a floater in the lane that made it a one-point game.
Saddiq Bey then stripped Howard on the ensuing possession with 14 seconds left. After a timeout, Booth drove but was trapped underneath, and passed the ball back to Samuels, who missed an off-balance jumper from the right side as time ran out.
Booth had 19 points and Eric Paschall 17 for Villanova (19-5, 10-1), which had won 11 straight since a 74-71 loss to Kansas on Dec. 15.
Howard hit 13 of 24 shots, including 5 of 11 on 3s. He made all seven of his free throws.
Marquette bounced back from its first home loss of the season, a 70-69 loss to St. John's on Tuesday. Sacar Anim added 18 for the Golden Eagles.
The Golden Eagles opened the second half with a 10-3 run, taking a 40-29 lead on a jumper by Sam Hauser with 16:38 left. Marquette pushed the lead to 47-32 on Anim's jumper as Villanova made just 2 of its first 12 shots after the break.
Villanova answered with 10 consecutive points, pulling within 47-42 on Saddiq Bey's 3-pointer from the right corner. The Wildcats later went on a 13-2 burst and took a 55-53 lead on Samuel's 3-pointer with 6:16 remaining.
Villanova: After facing Providence at home, the Wildcats play three straight on the road at St. John's, Georgetown and Xavier. Villanova earlier defeated all three at home.
Marquette: The Golden Eagles play three of their next four on the road, culminating in a rematch at Villanova on Feb. 27. Although dominant at home, Marquette is 5-3 on the road.
Villanova hosts Providence on Wednesday.
Marquette is at DePaul on Tuesday.
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