Patrick Cantlay held his nerve to come out on top in his duel with world number one Jon Rahm and win the Tour Championship, FedEx Cup title and 15million US dollar (£10.9million) first prize in Atlanta.

Cantlay carded a closing 69 at East Lake to finish 21 under par, a shot ahead of US Open champion Rahm, who carded a final round of 68.

“Felt like a huge win and it was,” said Cantlay, whose victory in the BMW Championship seven days ago meant he started the week on 10 under par, two shots ahead of his nearest rival and four clear of Rahm, under the controversial handicap system adopted in 2019.

“I played great today. It hasn’t even sunk in yet. I just kept telling myself to focus and lock in and I did a great job of that today. It was tough. It was definitely different than any other week. It was the longest lead I’ve ever held.

“But I just tried to stay, day after day in the present, and I did an amazing job of that this week because the last couple days I made some mistakes I don’t usually make and I was able to really centre myself and hit a lot of good shots when I needed to.

“We had distanced ourselves from the field and it was like a one-on-one match play feel, and I think it will be great practice for the Ryder Cup.”

Cantlay took a two-shot lead into the final round and moved further ahead with a birdie from five feet on the second, but there was a two-shot swing on the fifth as Cantlay three-putted from long range after a superb Rahm approach set up a tap-in birdie.

A birdie on the par-five sixth immediately restored Cantlay’s two-shot lead, only for the world number four to bogey the difficult par-three ninth after coming up short of the green.

After missing from short range for birdie on the 13th, Cantlay made no mistake on the 16th to double his lead, but bogeyed the 17th and had to match Rahm’s birdie on the par-five 18th to make sure of the biggest win of his career.