Trinity, the top-rated team in the tournament, had no problem passing its first-round test Wednesday in the Whitaker Bank/KHSAA Boys' Sweet Sixteen.
The Shamrocks dispatched Owensboro 55-41 before a Rupp Arena crowd of 11,566.
Craig Owens led the winners with 13 points and eight rebounds. Tré Ivory and Jax Levitch added 10 points each. And 6-foot-10 junior Ray Spalding totaled seven points, six rebounds, four blocks and three steals.
Trinity (30-5), which won the tourney in 2012, advances to Friday's quarterfinals to meet Hopkinsville, an 83-62 winner over South Oldham.
Owensboro, starting all juniors and making a record 42nd state tourney appearance, had a miserable day shooting — 11-for-43 (25.6 percent).
"They put a lot of ball pressure on us," Red Devils Coach Rod Drake said. "We couldn't advance the ball past the free-throw line and get it into our bigs. When we did get it inside, we scored but ... yeah, that's probably some of the best defense we've had."
Darion Morrow paced No. 11 Owensboro (21-11) with 13 points. Jaylin Kelly added 12, while Justin Miller had 11 points and 10 rebounds.
Owensboro missed its first seven shots and was 4-for-22 (18.2 percent) in the first half, which ended with Trinity on top 32-22. The Devils stayed reasonably close by knocking down 12 of 16 first-half free throws.
"I was just really proud of our effort," winning coach Mike Szabo said. "I thought we played extremely tough. I thought we played together, especially defensively. I'm really happy with our defensive effort. I thought we rebounded the ball pretty well; it could have been better.
"Overall defensively, I thought we did a nice job of containing shots, making it difficult for them. Offensively, I thought we got some good looks. We just didn't shoot the ball very well today (19-for-49, 38.8 percent), but we did enough to get out of here with a win."
Owensboro led only once in the early going, 3-1.
Second half, the Devils came no closer than 10 points and trailed by as many as 18.
"They were everything we thought they would be," Drake said. "We prepared well for them. They're No. 1 in the state for a reason. We played well. We dug ourselves in a hole early and we had to climb uphill the rest of the way. Against a good ball team, you can't do that. They exploited every weakness that we had."
Owensboro wanted to go inside to the 6-5 Miller and 6-6 Aric Holman, but had little success. Holman fouled out with no points and five rebounds.
"We really keyed in on those two guys," Szabo said. "We had to limit them. Miller, No. 55, he's a load in there. If he catches it on the block, he's going to score. So we wanted to kind of force him off the block, doubled him and, if he catches it low, we wanted to sit on that shoulder and force him the other way. Overall, I thought we did a good job."
Trinity wound up outscoring the Devils 28-8 in the paint and 13-1 on second-chance looks.
Next up for the Shamrocks will be Hopkinsville.
"A great challenge," Szabo said. "They remind me a lot of Ballard — very quick, very athletic. I really like their team. We've got to keep them off the backboard. We've got to take care of the basketball. They're aggressive defensively, and offensively. So no question it's going to be a great game on Friday."