Pinatubo began his career in an evening novice race at Wolverhampton on 10 May 2019, beating another Godolphin horse, Platinum Star by 3 1/4 lengths. This was followed by a win in the formerly Listed Woodcote Stakes on Oaks day at Epsom. On 22 Jun 2019, Pinatubo was the 3/1 second favourite for the Chesham Stakes at Royal Ascot but in the event, beat the favourite, the Aidan O'Brien trained Lope y Fernandez by 3 1/4 lengths, breaking the course record in the process. The horse then took a step up to win his first Group race, the Group 2 Vintage Stakes at the Glorious Goodwood meeting by 5 lengths on 30 July. For his first Group 1 race, the Vincent O'Brien National Stakes at The Curragh, he was ridden for the first time by William Buick, who had missed 12 weeks of the season following concussion. Pinatubo was made 1/3 favourite and won by 9 lengths from Armory, with the Racing Post referring to him as a "Ferrari of a racehorse" and trainer Appleby stating "he's the best two-year-old I've ever trained". Comparisons were drawn with two year old performances from horses like Frankel and Arazi. Following this victory, form analysts Timeform rated him the second best two-year-old of the modern era behind Celtic Swing On 12 October, Pinatubo ended his season in the Dewhurst Stakes at Newmarket and started the 1/3 favourite. His eight opponents included Wichita, Positive, Arizona and Mystery Power. After racing in mid-division he overtook the front-running Arizona in the final furlong to win by two lengths. In the official ratings for the 2019 season Pinatubo was rated 128, the highest two-year-old rating awarded since Celtic Swing was rated 130 in 1994.
2020: three-year-old season
The flat racing season in England was disrupted by the COVID-19 Pandemic and the 2000 Guineas was run a month later than usual on 6 June over the Rowley mile at Newmarket. Pinatubo started the 5/6 favourite against fourteen opponents but finished third behind Kameko and Wichita. Two weeks later the colt started favourite for the St James's Palace Stakes at Royal Ascot. After racing towards the rear of the field he took the lead approaching the final furlong but was overtaken in the closing stages and beaten a length into second place by Palace Pier. On 12 July Pinatubo was sent to France and started the 3/5 favourite for the Group 1 Prix Jean Prat, run over 1400 metres at Deauville Racecourse. His ten opponents included Alson, Tropbeau, Molatham, Arizona, Wooded and Kenway. Ridden by Buick, he was restrained towards the rear of the field before moving up to take the lead 200 metres from the finish and kept on well under pressure to win by three quarters of a length from the 40/1 outsider Lope Y Fernandez. Buick commented "He felt really good today. He showed his brilliance, he showed how fast he is, and I think coming back to seven furlongs was a little bit easier for him... At Ascot, he did absolutely nothing wrong and he was just outstayed by a horse who was on the improve and was stronger at that trip on that day. But I think he showed his resilience and constitution to come out of that race and do what he did here".
