"At halftime, Coach (Mark Gottfried) talked to us and said we had a really good half defensively," Turner said. "So he said if we had a good second half defensively, then the offense would come. I think the second half was a testament to that."
Anthony Barber added 16 for the Wolfpack.
The Tigers (16-13, 8-9) rallied late to cut what had been a 16-point deficit with just under three minutes to play to five at game's end.
Gabe DeVoe scored 18 points off the bench late for Clemson. Dante Grantham added 12 points.
But the Tigers struggled to score points against a stingy N.C. State defense that Gottfried described as, "locked in."
"I thought our defense won the game for us tonight," Gottfried said. "Then, Ralston got some things going in the second half. He made some shots. It loosened some things up for our team, and we gained some confidence off of Ralston's shooting. That was really big for us. But from tip to buzzer, I liked how we guarded them. I thought we did a good job."
The victory was N.C. State's fourth in their last five ACC contests and puts the Wolfpack in sixth place tie with Syracuse behind No. 19 North Carolina in the ACC standings.
The loss was a missed opportunity for the Tigers, who have now lost three of their last four outings, as they attempted to win nine ACC contests for just the 10th time in school history.
DeVoe's 3-pointer with 3:26 to play ended Clemson's long dry spell from the field.
After a sluggish start that included 6 of 24 shooting (25 percent) in the first half, the Wolfpack found enough offense and built what became an insurmountable lead after trailing 21-20 at the break.
"(Clemson) is hard to score on," Gottfried said. "It's just hard. At halftime, it's 20-21, and I felt good. We only had 20, but they only had 21."
Clemson, which lost for the third time in four games, connected on just 20 of 67 shots (29.9 percent) from the floor, including 5 of 20 (25 percent) from 3-point range. DeVoe hit 3 of 7 3-point attempts, while the rest of the Tigers connected on 2 of 13 (15 percent).
Tigers head coach Brad Brownell said he was disappointed in his team's second-half defense, which allowed 46 points over the final 20 minutes, but saw his players become tentative on offense as their scoring drought continued to grow.
"We never really got stops, so we never got into transition to get an easy basket or two," Brownell said. "Sometimes, you just need an easy basket or two so you can take a deep breath. . . We just don't shoot it very well, and we never got any of those easy ones. That put pressure on us, and we kind of played like we had a piano on our back."
The victory was N.C. State's 100th in the long history between the two schools. The Wolfpack leads the series 100-60.
Clemson: Tuesday was the final game at Clemson's Littlejohn Coliseum until November 2016. The facility will undergo an extensive renovation. The Tigers will play next season in Greenville, S.C. at the Bon Secours Wellness Arena before returning to the revamped Littlejohn in 2016.
N.C. State: Guard Trevor Lacey was one of 16 finalists named this week for the Jerry West Award, which goes to the nation's top shooting guard. Lacey, who scored 10 points against Clemson, is sixth in the ACC in scoring, averaging a team-high 16.2 points per game to go along with 4.6 rebounds and 3.4 assists per game.
Clemson concludes its regular season Saturday at No. 12 Notre Dame.
N.C. State ends its regular season Saturday at Syracuse.