Bryson DeChambeau was branded “stupid” by his own equipment manufacturers in an extraordinary war of words in the aftermath of his first round at The Open.

DeChambeau posted a wayward 71 at Royal St George’s and stated that his driver “sucks” but his comments provoked a withering response from Cobra, the company which provides the former US Open champion’s clubs.

DeChambeau believes the inability to find a driver compatible with his fierce swing speed is hampering his progress and the 27-year-old said: “The driver sucks. It’s not a good face for me and we’re still trying to figure out how to make it good on the mis-hits. I’m living on the razor’s edge.”

Cobra’s tour operations manager, Ben Schomin, hit back and told USA Today: “Everybody is bending over backwards. We’ve got multiple guys in R&D (research and development) who are CAD-ing (computer aided design) this and CAD-ing that, trying to get this and that into the pipeline faster. Bryson knows it. It’s just really, really painful when he says something that stupid. It’s like an eight-year-old that gets mad at you.”

DeChambeau later issued an apology via Instagram.

"The comment I made in my post round interview today was very unprofessional," DeChambeau said in his statement. "My frustration and emotions over the way I drove the ball today boiled over. I sucked today, not my equipment. Cobra and I have worked together for over five years and they are some of the hardest working people in [the] golf industry and make an incredible product. Their team is like family to me, especially Ben Schomin, who has been there for me every step of the way since I started my career.

"I deeply regret the words I used earlier. I am relentless in pursuit of improvement and perfection. Part of that causes me to become outwardly frustrated at times. With the new speeds I am obtaining, my game is a constant work in progress and so is controlling my emotions."