Leading from start to finish, Xaba crossed the line in 33 minutes and 13 seconds to claim the R30 000 prize, with Ethiopia’s Selam Gebre coming in second in 33:18, and Karabo Mailula third in 33:33 in a field of 16 000 runners.
The Boxer Running Club star mirrored her strong start from last year’s first leg in Cape Town, capitalising on ideal weather conditions, but she expressed disappointment with her race pace.
"I am happy that I won the race, but unhappy with the time. My body did not respond the way I wanted," said Xaba.
"Today, I saw a group of South African women behind me, but it was not a challenge, and no one wanted to overtake me. I was thinking maybe I could get strong competition."
Xaba, coached by two-time women's 800m Olympic champion Caster Semenya, is enjoying a rich vein of form after earlier winning the 5 000m, 10 000m, and 21.1km events at the Athletics Gauteng North Championships.
She is now targeting further improvement in the track and field events, with qualification for this year's World Athletics Championships in Tokyo, Japan at the top of her agenda.
“My form is good after the half-marathon, but I would like to do more when it comes to track and field. I would like to run a personal best in the 21km and the 10 000m," she added.
"The goal now is to try and qualify for the World Championships later this year."
Xaba is on the verge of making history by joining Tadu Nare, Irvette Van Zyl, and Rene Kalmer as a three-time Grand Prix series winner, should she continue defending her race titles across the country.
Confident in her abilities, she believes she can achieve this milestone.
“About the Spar Grand Prix record, yes, I am looking forward to winning the series for the third time and I must focus on myself.
"I know that the competition will be tough, but I would like to join the three ladies as one of the [most] successful runners in the competition,” Xaba concluded.