Leslie scored all 19 of his points in the final 23 minutes to lead No. 23 North Carolina State to an 84-68 victory over Western Michigan on Saturday.
"He played pretty good," N.C. State coach Mark Gottfried said. "I don't want him to flip the switch. I want him to play that way all the time."
Richard Howell added 18 points on 8-of-8 shooting for the Wolfpack (10-2), who won their sixth consecutive game.
N.C. State committed a season-low eight turnovers and shot 55 percent from the field, padding its NCAA-leading field goal percentage.
T.J. Warren scored 15 points, Scott Wood had 11 and Lorenzo Brown added 10 for the Wolfpack.
Leslie had 14 points, six rebounds and three steals after halftime.
"It was just me realizing that I'm a leader on the team and that I had to pick it up," Leslie said. "That was it. The first half, I had to pick it up. I said it to myself, and that's what I had to do."
Nate Hutcheson scored 16 points to lead the Broncos (8-5), who shot 36 percent. Shayne Whittington added 14 points and Darius Paul had 12 for Western Michigan.
The Wolfpack built a 43-36 halftime lead, shooting 60 percent from the field behind a 7-for-7 effort from Howell.
The Broncos pulled within 43-38 early in the second half, but they got no closer. N.C. State used a 12-2 run to take a 62-44 lead with 11 minutes remaining.
"I thought the difference between the first half and the second half was North Carolina State's defense," Western Michigan coach Steve Hawkins said. "They picked up the pressure a lot more and took us out of rhythm a little bit."
N.C. State scored at least 80 points and shot better than 50 percent from the field for the fifth straight game.
Howell scored 10 of the Wolfpack's first 16 points, shaking off a foul-plagued, scoreless outing a week before against St. Bonaventure.
Howell left the game against Western Michigan with an injury to his left ankle early in the second half, but he returned less than 3 minutes later.
"Of all the teams we've played so far - and we've played some pretty good teams - if there's a player I could take off of any of those teams, it would be Howell," Hawkins said. "I just love the way that kid plays. He's a beast."
Western Michigan hung tough early on the strength of its offensive rebounding, outscoring the Wolfpack 16-6 on second-chance points in the first half.
N.C. State gained its cushion after a spurt by Leslie.
Leslie went to the bench with 9:18 remaining in the first half after Western Michigan scored for the fourth time on a putback.
Leslie returned to the game at the 3:35 mark with the score tied at 32.
He delivered a three-point play on N.C. State's next possession to spark a 9-0 run, then capped the spurt by reaching a career milestone in unusual fashion.
Leslie came up with a steal in the open court and dribbled toward the basket. He slowed to gather himself for a windmill dunk, and Hutcheson caught up and hacked him on the arm. Official Roger Ayers checked the courtside monitor to see if the foul was flagrant, but he kept it a common foul.
Leslie made both free throws to give the Wolfpack a 41-32 lead, becoming the 46th player in N.C. State history to score 1,000 points.
After that, he took over the game.
"He was a lot more active," Gottfried said. "As the game wore on, he's blocking shots, getting rebounds, running the floor. It's a different player. He's got to play that way all the time."