Naeem Jack broke the SA 110m junior hurdles record on Thursday, clocking 13.16 seconds in the heats in the colours of host Western Province Athletics, despite running into a slight headwind.

This was when South Africa's brightest young prospects flaunted their talent on the opening day of the ASA U16, U18, U20 and U23 Track and Field Championships at Green Point Athletics Stadium in Cape Town.

Admitting he was surprised by his time, Jack said he wasn't putting pressure on himself to go quicker in the final on Friday, and he was more focused on securing the ASA junior title.

"The goal was just to come out here in the heats and execute, put a good race together and hopefully get a good time," Jack said.

"But when I saw the conditions I thought 'let's just take it easy'. I wanted to run a clean race, clear all the hurdles and run through the line, and luckily I got a good time and I'm really happy with my performance."

Sprint sensation Bayanda Walaza (Athletics Gauteng North) delivered in style, storming to victory in the U20 men's 100m final in 10.26 seconds as he held off a challenge from Karabo Letebele (Athletics Vaal Triangle) who grabbed the silver medal in 10.33 in one of the most anticipated races of the championships.

World junior champion Walaza said he was delighted to pick up another title.

"It's nice to come here and compete against such great athletes," Walaza said. "There were some fast athletes here and it's fun to run against them... so I enjoyed every moment. The crowd was very supportive, so I want to thank them.

"I'm reaching for the sky, and for each and every achievement I take it as an assessment to open doors for the next assignment and I will use this to unlock other chapters."