After school, Blewett joined the academy of KwaZulu-Natal's professional rugby team, the . He was included in the squad that participated in the
2015 Under-19 Provincial Championship, and started each of their twelve matches in the competition. He scored tries in matches against , and – in both their home and away clashes – before ending the season with two tries in their final match against Free State U19. Despite Blewett's six tries (and a single conversion for a season tally of 32 points), the Sharks endured a poor season, winning just one match and finishing bottom of the log. Blewett started the 2016 by participating in the
2016 Varsity Shield for . He featured in all eight of their matches, scoring seven tries; he scored one try in their opening round victory over and one a fortnight later against before getting two tries in a 63–30 win over in his fourth appearance. One try followed in a 16–44 defeat to before another two-try haul in their 97–0 win over the UFH Blues. Blewett's total of seven tries was the second-most by any player in the competition, behind team-mate Thobekani Buthelezi, and helped UKZN Impi to second spot on the log. However, the Varsity Cup Executive Committee ruled that UKZN Impi fielded an ineligible player throughout the season and imposed a twelve points deduction, which cost UKZN Impi a place in the
Varsity Shield final and a
Varsity Cup promotion play-off against . After the Varsity Shield, Blewett linked up with the squad that participated in the
2016 Currie Cup qualification series. He made his first class debut on 23 April 2016, coming on as a replacement in their 48–18 victory over
Namibian side the , and made a second appearance four weeks later in a 16–53 defeat to a . He spent the rest of the season playing in the
2016 Under-21 Provincial Championship for the team, where he scored six tries in six appearances to end as the joint-top try scorer in the competition. He scored single tries in matches against and before scoring two tries against and . The team finished in sixth spot to miss out on the title play-offs. At the end of October 2016, Blewett was included in the
Super Rugby squad for the
2017 season. ==2018: Southern Kings==