In 2014, he finished third in the autocross class of the Finnish Rallycross Championship, reaching the rostrum during a one-off outing in the World Championship-supporting RX Lites category on home soil at Kouvola along the way. A year later, he piloted an Olsbergs MSE-run Ford Fiesta Supercar to the Finnish title, while making his World RX bow that same summer at Höljes in Sweden.

After contesting the off-season RallyX on Ice series at the beginning of 2016, Grönholm committed full-time to World RX, completing his maiden full campaign in the championship with OMSE before switching to the family-run GRX outfit in 2017, securing his first final appearance with fifth position in Germany.

2018 marked a significant step forward for the Finn, with four visits to the final behind the wheel of the new Hyundai i20 yielding seventh place in the overall classification – comfortably the top independent entry.

That paved the way for a full-on title tilt the next season, when a brace of triumphs and two further podiums saw Grönholm wind up just 25 points shy of the Drivers’ crown, despite missing two rounds due to appendicitis. His points-per-event tally was the highest in the field.

Another race win in 2020 cemented fourth spot in the standings for the second consecutive campaign, while 2021 would prove to be the Kauniainen native’s most successful to-date, as he matched eventual champion Johan Kristoffersson for victories en route to third in the title table. Grönholm replicated that result the following season – the first of World RX’s electric era – courtesy of a seventh career triumph and three additional rostrum finishes as Construction Equipment Dealer Team made its series debut.