Heslip scored 18 points, with all five of his 3-pointers coming in the second half, and the Bears got a much-needed boost with a 74-61 victory over No. 16 Iowa State on Tuesday night. His tiebreaking 3 with 2:14 left started a game-ending 13-0 run.
''You guys don't know how happy I am right now. All I wanted to do was win. I just wanted to leave everything out there so we could win,'' Heslip said. ''This was the best feeling I've felt in this gym, no question.''
There were 15 lead changes and four ties before Heslip put the Bears (20-10, 8-9 Big 12) ahead to stay.
And now the Bears, who have won seven of eight games since starting 2-8 in Big 12 play, feel confident they have what's needed to get back in the NCAA field after having to settle for the NIT championship last season - a year after making it to an NCAA regional final.
''Absolutely. No question,'' Baylor coach Scott Drew said. ''You can't hold losses against Top 25 teams in the top conference in the country (against us). Minnesota was 8-10 last year. They lost their last three out of four - and they got in. ... You've got to be thankful for the league's strength and playing in a great league.''
Iowa State (22-7, 10-7), in the mix for the No. 2 seed in next week's Big 12 tournament, lost its second road game in four days.
The Cyclones, who lost at Kansas State on Saturday, were held under 70 points for the first time this season. Melvin Ejim, the Big 12's leading scorer, had only six points - 13 below his average.
The Cyclones didn't score after DeAndre Kane's wide-open 3 tied the game at 61 with 4:10 left. That was their 12th 3-pointer in the game, only the second after halftime.
''We'll be fine. Hey, we lost two road games in the Big 12 Conference,'' coach Fred Hoiberg said. ''We're not the only team that that's happened to. ''
Cory Jefferson, like Heslip a Baylor senior playing his final home game, had 21 points and seven rebounds. Kenny Chery, a junior college transfer who took over as the Bears' point guard this season, finished with 16 points and two long jumpers after Heslip's go-ahead shot.
Royce O'Neale had 11 rebounds for Baylor, which is at Kansas State on Saturday.
Kane had 20 points for Iowa State and Dustin Hogue added 12 for the Cyclones, who are home Saturday against Oklahoma State.
Heslip missed his only two shots before halftime, when his only points came on three free throws after being fouled and knocked down taking a long-range shot with 36 seconds remaining in the half. That gave the Bears a 36-35 lead.
After halftime, Heslip gave the home crowd another look at his long-range shooting.
''Every single timeout, I kept telling everybody, 'Just leave everything out there.' I wanted to win so bad,'' Heslip said. ''The team did that.''
Heslip made three 3s in a span of 1:47 early in the second half, taking it from a tie game to a 46-40 Bears lead. The first two came on passes from Chery, and the third came after Gary Franklin - the third Baylor senior - had a steal and the assist.
The final go-ahead 3 by Heslip came after Chery got a long rebound to start a break. The pass went to Heslip on the right wing, where he made a fake-pump and a step to the left before knocking down the shot.
Ejim, playing on his 23rd birthday, missed his first eight shots before consecutive layups midway through the second half put the Cyclones up 49-48. The second layup came after a steal by Hogue. Ejim finished 3-of-14 shooting, missing all five of his 3-point attempts, and had nine rebounds.
''Easily a big-time win for us. Iowa State is a great team. They were a tough team when we played them at their house. They always are,'' Jefferson said. ''They've been a tough team throughout the whole conference. They're one of the top teams. It's definitely a good win for us.''