And given Peterson had not been eliminated before the quarterfinal stages when she had competed in the event since 2014, the Kiwi was tasked with taking on one of the break's best.
It was a timid start to the heat from both surfers, with the receding tide seeing the wave face steepen.
After exchanging sub-one point rides, Hareb took the front foot in the heat, linking a couple of turns together to post a 2.93.
She followed that with what ended up as her two counting waves - a 3.93 and 4.87 - however her flow between turns was a bit static and likely saw her scored a touch lower that she was capable of scoring on those rides.
Still, the Kiwi held the lead over the half-way point in the heat, but with Peterson posting a 5.17, she was close behind.
With less than 10 minutes to go in the 30 minute heat, last year's event runner-up showed how important flow was. Peterson glided on her backhand to link three quality manoeuvres and post a nine-point ride to comfortably win the heat.
Hareb takes a 13th place for the event with the loss, but was in good company. Former CT event winners Sage Erickson and Nikki van Dijk were also second-round casualties.
It won't be long between events on the CT, though. Hareb's next chance to perform on the sport's top level arrives when the Rip Curl Pro gets underway at Bells Beach in Victoria on March 28.
