Molinari, who started the day tied with the Northern Irishman at the top of the leaderboard, took control early in the round and then refused to release his grip on one of the most coveted trophies in professional golf. In the end, he was in cruise control.
Where McIlroy, who had led by three after 36 holes, was wayward off the tee, Molinari was precise and measured. He first opened a gap over the world No.8 and pre-tournament favourite with a birdie at the 3rd hole and extended the lead to three with two more, at the 4th and 8th.
With an outward half of 32, he came home in 36 for a 17-under-par total of 271 and victory by two strokes over McIlroy (70) and three over Alex Noren (SWE), the 2017 champion, and Lucas Bjerregaard (DEN), the first round leader.
“If feels amazing,” the delighted winner said. “I have been close many times and now I’ve finally got across the line. If I picked one tournament to win, it would be the BMW PGA Championship.” With the trophy came a first prize of €1 million.
On presenting Molinari with the trophy, Dr Ian Robertson, BMW Group, said: “I would like to offer my heartfelt congratulations to Francesco for a fantastic victory in the 2018 BMW PGA Championship.
“I would like to say how honoured we are to be the title partner of this flagship event for the fourteenth consecutive year. There is such a great atmosphere here. This venue always has a special feeling and you can really sense everyone’s passion for this championship.
“During a week with phenomenal displays of tenacity and athleticism, backed by incredible crowds, I think we can agree that the BMW PGA Championship exceeded all expectations.”
With Molinari and McIlroy holding a lead of four strokes over their nearest challengers, the final day was billed as a two-horse race. By halfway, however, it was all about the front-runner. Molinari rarely strayed off the fairways and let his rivals take the risks involved in trying to catch and overtake him. They got nowhere near.
For his part, McIlroy was keen to take the positives out of the week. “It's close, it's very close,” he said. “I've given myself a great chance here this week. I didn't quite pull it off but it's not far away. I get a bit down on myself because my expectations are high, and with a 36-hole lead, I should have closed it out. But that's not taking anything away from Francesco. He played a great weekend and bogey-free around here is some playing.”
The champion dropped only two shots in four rounds, the last of them at the 10th hole of his second round. In winning, he became the third Italian to lift the trophy, following Costantino Rocca (1996) and Matteo Manassero (2013). His victory also kick-started his summer campaign to qualify for the Europe Ryder Cup team that will play the United States in Paris this September.
Something of a West Course specialist, Molinari had five top-ten finishes in his previous six appearances at Wentworth and finished runner-up to Noren in 2017. Now he has gone one better and will already be thinking of the defence of his crown in 2019. He will take some stopping.