After high school, Stighling moved to Pretoria to join the academy. He made nine appearances for their Under-19 team during the 2012 Under-19 Provincial Championship, scoring tries against, and to helpthe BlueBulls into the semi-finals by finishing second on the log. Stighling played off the bench in their 46–35 victory over the team in the semi-finals and started the final, where his side lost 18–22 to Western Province in Durban. He was included in the squad that played in the 2013 Vodacom Cup and made his first class debut by coming on as a replacement for the final half an hour of a 54–26 victory over trans-Jukskei rivals the, his only appearance in the competition. He made eight starts and one appearance as a replacement for the team in the 2013 Under-21 Provincial Championship. He scored tries against Border and the Free State during the regular season as his team won eight of their twelve of their matches, but didn't feature in the title play-offs, as the Blue Bulls reached the final before being beaten by Western Province. Stighling played for in the Varsity Cup at the start of 2013. He made seven starts for the university team and scored one try against Gauteng rivals. He started his second season with the Under-21 team in great fashion, scoring two tries in a 143–0 victory over. He scored further tries against the golden Lions, Leopards and Western Province as his team finished in second place to qualify for the title play-offs. He started both their 23–19 victory over the Golden Lions in the semi-final and the final, where his side got the better of Western Province, winning 20–10 in Cape Town. Almost two years after his first class debut, Stighling made his second senior appearance, coming on as a replacement for the Blue Bulls against the in the 2015 Vodacom Cup. A week later, he scored his first try in senior rugby, scoring just after the hour mark in a 46–25 victory over a. After a further two appearances off the bench, he made his first start in a Blue Bulls shirt in their 44–0 win over Namibian side the in Windhoek. He also started against the a week later and made his third start and seventh appearance of the season in the semi-finals, with his side losing 6–10 to the to be eliminated from the competition. He was a key player for the Blue Bulls in the 2016 Currie Cup qualification competition, starting thirteen of their fourteen matches. He didn't score in the first eleven of those appearances, but got a try in a 45–26 over the in East London and then scoring four tries in a 95–12 win over the in Pretoria a week later. Stighling was included in the Blue Bulls squad for the 2016 Currie Cup Premier Division and named in the starting line-up for their opening match of the competition against. In addition to making his Currie Cup debut, he also scored a try in the 47th minute of the match to help the Blue Bulls to a 45–26 win.
