Dayton, Ohio ? Melvin Johnson III insists he’s in a deep shooting slump.

Oh, really?

The smooth guard with “SWISH” scrawled on the side of each orange shoe scored a career-high 29 points Wednesday night, putting on the most scintillating show so far in the NCAA tournament while leading Texas-San Antonio to a 70-61 victory over Alabama State in the “First Four” round.

“It seems like the last four or five games, I can’t make a shot,” Johnson said. “I have ‘SWISH’ on the side of my shoes because I used to make shots. I might have to black it out for now.”

No need to edit the footwear, not after that NCAA tournament debut.

The Roadrunners (20-13) and their smooth guard head to Cleveland for a game Friday against top-seeded Ohio State, which won’t allow all those open shots.

“No. 31, if he’s on like he was tonight, it should be a pretty good game,” Alabama State’s Jeff Middlebrooks said.

Against Alabama State (17-18), Johnson took advantage of every opening. The sophomore had a career high in the first half alone, when he outscored the star-struck Hornets 25-21.

Middlebrooks and Tramayne Moorer had 12 points apiece for Alabama State, which had the worst record in the expanded 68-team tournament.

“We let a guy get 25 points in the first half,” Moorer said. “He outscored us!”

The Roadrunners came to Dayton with a stated goal: San Antonio had never won an NCAA tournament game of any sort. Now, they’ve got reason to raise a banner in their 4,080-seat UTSA Convocation Center.

“Our first win in an NCAA tournament game in any sport — we’re very proud to be in this moment,” coach Brooks Thompson said.

Might as well let Johnson pick the spot to place the banner.

The 6-foot-5 guard did everything Wednesday. He scored off drives to the hoop and made fall-away jumpers from every spot, hardly missing in the decisive first half. Johnson was 8 of 14 from the field, making one less field goal than all the Hornets combined.

“Johnson got good look after good look, and he also made some tough shots,” Hornets coach Lewis Jackson said. “He got on a roll and it trickled down to everybody else.”

Johnson also got to shoot four free throws after a pair of technicals on the Hornets. He made ’em all, of course.

He even connected while sitting on the court after getting fouled in the second half. He playfully flipped the ball at the basket, and it went in. He took only four shots in the second half.

UTSA’s front line took control during a 17-4 opening run that put the scent of a blowout in University of Dayton Arena. The Roadrunners got 14 of the first 18 rebounds, repeatedly giving themselves second chances after a miss.

Johnson turned those extra chances into his showtime. He made a 3 that built the lead to 31-13. Next time down the court, he was feeling so comfortable that he quickly got off a long 3 that came up short of the rim for one of his few misses

While a smattering of Alabama State fans chanted “Air Ball,” Johnson turned away and smiled. So did Thompson, who couldn’t blame him for shooting away.

Johnson sent a stir through the crowd with an emphatic, breakaway dunk that built the lead to 38-15 with 3:50 left in the opening half and showed that the Hornets had no chance of slowing him down. By then, he already had 21 points, three shy of his previous career high.

The low point for Alabama State? Robert Sanders tried to dunk off a rebound and missed, then hung on the rim and drew a technical foul. Johnson made the two resulting free throws.

UTSA stretched the lead to 28 points early in the second half. Alabama State went to a swarming full-court press and got the lead down to 64-55 with 2:54 to go, but the comeback stalled there.

The Hornets reached the NCAA tournament without ever having a winning record during the season.