The Musketeers (13-5, 4-1 Atlantic 10 Conference) took control with an 18-2 run early in the second half led by their senior point guard, who took only five shots and had six points.
Xavier had four players in double figures. Kenny Frease scored 13, and Dez Wells and Jeff Robinson had 12 each.
Xavier extended its A-10 record to 43 consecutive league wins at home. The Musketeers haven't lost an A-10 game at the Cintas Center since Saint Joseph's beat them 68-58 on Feb. 28, 2006.
The Hawks (12-7, 2-3) couldn't overcome Xavier's second-half run or the loss of guard Carl Jones, who leads the league in scoring with 17.2 points per game. Jones sprained his left ankle during a loss to Massachusetts on Saturday and didn't play.
Halil Kanacevic led the Hawks with 13 points and 14 rebounds.
With Jones out, the Hawks' Langston Galloway became a focus of Xavier's defense. Galloway is the A-10's top 3-point shooter and makes 51 percent overall. He kept the Hawks in it during the first half, scoring 12 points.
The Musketeers clamped down in the second half, limiting Galloway to only one more basket and 5-of-14 shooting overall.
Xavier got the better of the long-range shooting at the outset. Lyons made his first three 3-point attempts during an opening 24-14 run. Wells had the highlight play, taking the ball around his back while getting fouled for a layup. He made the free throw for a three-point play.
Galloway made a 3-pointer and a four-point play - Lyons fouled him beyond the arc - during a 14-4 run that put the Hawks up 33-32. They led 39-37 at halftime, with their rebounding making the difference in an otherwise even game. Kanacevic got 10 rebounds in the half.
Holloway led the decisive 18-2 run with four assists and a driving layup. Wells scored six points during the spurt that put Xavier ahead to stay 55-45 with 11:48 left.
Holloway also moved over and did most of the work guarding Galloway, who missed his four shots while Xavier pulled away. The Musketeers led by as many as 17 in the second half.