Having never reached the Semi-finals at Roland Garros before this year, the Finnish/British pair now have the opportunity to add the French Open to their 2024 Wimbledon and 2025 Australian Open crowns.
The second seeds will face either first seeds Marcel Granollers and Horacio Zeballos, or fifth seeds Simone Bolelli and Andrea Vavassori in what is set to be a high-quality Final on Saturday 6th June.
Local favourites Halys and Herbert were the fifth unseeded duo to have come up against Heliovaara and Patten in the tournament so far, and while the Final will be a step up in class, there is no doubting the pair's form - they have won all 10 of their sets so far without needing a tiebreak, including in this match where they were up against a two-time champion and career Grand Slam winner in Herbert.
The latest two of those were wrapped up in one hour 16 minutes - in the firsr set, the breakthrough came in the sixth game, when a pair of unforced errors and a double fault from Herbert handed a 4-2 lead to the Finn and Brit, who then both held serve comfortably to take the opener, 6-3.
The pressure appeared to be getting to Herbert as his serve began the second set, but another two double faults put the Frenchmen on the back foot, and Heliovaara and Patten broke serve again.
However, they came close to breaking back in the fourth game, going 40-0 up only for Heliovaara to save three break points, which included a rare ace from the 36-year-old.
That was the closest the French pair came, and though they managed to save two match points when serving in game nine, Heliovaara and Patten got the job done on the Essex man's serve in the next game to secure a 6-3, 6-4 win for a place in the Final.
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