Torin Dorn added 17 points for the Wolfpack (19-8, 7-7 Atlantic Coast Conference), who blew a 14-point second-half lead and had to survive BC's shot for the win at the end of regulation.
"I just play with a lot of fire," Daniels said. "I feel like I haven't been doing that for some of the season, so I'm just trying to get that back and play how I play."
But N.C. State ran off the first seven points of the extra period, getting a 3-point play from C.J. Bryce on a reverse layup through contact followed by Daniels' stickback and Dorn's tough hanging shot.
"The game actually ended the way I told our guys it would," said NC State coach Kevin Keatts. "What another great ACC game. I told our guys that going into every game from this point on, we have a small margin for error and every game could possibly come down to the last second. Surely, I didn't expect overtime."
Daniels followed with a 3-pointer a short time later for an 83-75 lead with 2:11 left, a margin that would not get closer than seven points again.
"He is understanding how he can help his team," Keatts said of Daniels. "That being said, I thought he was great defensively. When you look at his five steals, you have to talk about that. He also scored the basketball for us. We have talked a lot about everybody having to sacrifice a little bit of their offense to help our team win."
Nik Popovic scored 18 points for the Eagles (13-12, 4-9), who trailed 64-51 with about 11 minutes left before using a 16-0 run to turn this into a fight to the horn.
BC had arrived with momentum with wins against Pittsburgh and Miami, then climbed back in this one when it threatened to get away from the Eagles. But Ky Bowman's missed 3-pointer to close regulation ended up being their last best chance, with N.C. State controlling the extra period from the start.
"Based on the way we practice and the way we condition, we get stronger as the game goes on," Dorn said. "In overtime periods we are able to outlast teams and show our conditioning off a little bit."
It didn't help that the Eagles had to play after halftime without Jordan Chatman, the team's No. 3 scorer (13.8 points) who left shortly before the break with an apparent hand injury.
Bryce added 17 points for the Wolfpack.
N.C. State hosts Wake Forest on Sunday. Boston College visits Clemson on Saturday.