[1][2] At the 2017 FINA Diving Grand Prix stop in Madrid, Spain, Heslop won the bronze medal in the 10 metre platform with a score of 391.15 points.

[12] Heslop won the bronze medal in the 10 metre platform event behind Xiaohu Tai and Bowen Huang, both of China at the 2018 FINA Diving Grand Prix stop in Madrid, Spain in July with a score of 390.60 points.

[14] At the 2019 Red Bull Cliff Diving World Series stop in Bilbao, Spain in September, Heslop became the youngest diver to win a medal of any kind at a Red Bull Cliff Diving World Series, winning the bronze medal with a score of 384.60 points.

[17] Heslop won the gold medal in the 27 metre high dive event with a score of 436.90 points at the FINA High Diving Qualifier held as part of the Abu Dhabi Aquatics Festival in Abu Dhabi, United Arab Emirates in December, earning first-place less than five points ahead of silver medalist Cătălin Preda and bronze medalist Constantin Popovici, both of Romania.

[22] His execution of the 6.2 difficulty dive earned him the number four top moment from the 2021 World Short Course Swimming Championships and the Abu Dhabi Aquatics Festival by FINA.

[1] In April, Heslop was officially announced as one of 16 permanent divers for the 2022 Red Bull Cliff Diving World Series.

[28] At the first stop of the 2022 Red Bull Cliff Diving World Series, held on 4 June in Boston, United States, Heslop won the title across all rounds of competition with a score of 462.50 points, which was over 30 points ahead of the next-highest scoring competitor, and marked his first time winning a gold medal at a Red Bull Cliff Diving World Series event.

[32] In the final of the mixed 10 metre synchronized platform the following day, he and his partner Ruby Thorne made their debut at an international championships, placing eighth with a score of 284.28 points.

[33] For the 2022 European Aquatics Championships, held in August in Rome, Italy, Heslop entered to compete in the 27 metre high diving event.