The 53-year-old, who’d started the final day with a three-shot lead after a brilliant 64 on Saturday, recovered from finding himself playing catch up late on to win the Riegler and Partner Legends at Murhof Golf Club in Austria.
It was mission accomplished for McIntosh, who returned to the amatuer ranks, winning the Scottish title at Blairgowrie in 2018, to get himself ready for a crack in the over-50s game.
“It’s fantastic,” he said after signing for a closing 73 to finish on 10-under, one shot ahead of 11-time Sunshine Tour winner James Kingston.
Former Ryder Cup player Joakim Haeggman finished one further back alongside European Tour winner Marc Farry and 12-time Sunshine Tour champion Adilson Da Silva.
“I didn’t play very well today,” added McIntosh, who is based at Turnhouse. “I was nervous at the start, and everything I tried to do just didn’t seem to come off.
“But I was watching the scoreboard the whole way round so I kind of just knew how to get it over the line.
“I think because of everything that surrounds it that makes it difficult including press, that is in the back of your mind, I slept okay last night though.”
The Scot parred the last five holes to get his nose back in front, with play being suspended for a short spell due to heavy rain. “I wanted to keep going,” he said of that delay.
“But James was really unlucky because he played 15 in a downpour, so we got a big break there.”