The 34-year-old prevailed 6-7(4) 6-4 6-3 on a sunlit centre court where interminable rallies regularly surpassed 30 shots.

Simon will face either Canadian teenager Felix Auger-Aliassime or Spanish 37-year-old Feliciano Lopez in the final when he will hope to become the first French winner of the prestigious pre-Wimbledon title.

After spending three hours 20 minutes to get past compatriot Nicolas Mahut on Friday – the longest match at Queen’s since 1991 – it was surprising to see Simon outlast a player 11 years his junior.

Russian Medvedev appeared to have seized the upper hand when he took the opening set on a tiebreak in which he won a 45-stroke rally at 4-3, but he looked rattled from the moment service breaks were traded early in the second set.

With both players adopting almost identical tactics, it felt more like a chess match than a grasscourt tennis duel at times but it was Simon who began to make the better moves as he worked his way back to level the match.

Simon saved a break point at 1-1 in the deciding set, this time catching the baseline with a backhand to end a hypnotic 49-stroke exchange.

Medvedev, clutching his back at times and leaning on his racket like a crutch, looked a spent force and a double-fault cost him his serve at 3-4. Simon then sealed victory in emphatic style to become the first French finalist here since Jo-Wilfried Tsonga in 2011.