Legendary ABC announcer Bob Rosburg learned a lesson about doubting the brilliance of Jack Nicklaus at the 1975 PGA Championship.

The Ohio native was roared on by a home crowd at Firestone Country Club as he chased the Wanamaker Trophy, but with the tournament in the balance during the third round, Nicklaus found himself in trouble on the 16th hole after his drive plummeted into the water as he pursued his fourth PGA triumph.

Rosburg, who pioneered on-course reporting on live TV, did not like Nicklaus' chances, to say the least, telling viewers that "the Golden Bear" was "dead" after finding a gruesome lie behind a tall tree, staring a big number in the face.

It turns out Rosburg, a winner of the PGA Championship himself in 1959, was not just speaking to viewers at home. His comments were overheard by Nicklaus, who sought to prove him wrong.

Nicklaus said in a documentary about his victory that he could vividly remember the scene as Rosburg talked down his chances of mustering a miraculous escape before being stunned by Nicklaus' courage and execution.

"He's dead. He's got no chance. He's got to pitch out," Nicklaus recalled Rosburg saying. "What in the world is he doing? He's going to try to hit the ball over that tree. He's dead. He can't do that."

Nicklaus made a habit of leaving his doubters looking foolish, typically finding a way to muster a Houdini-like escape like the one at Firestone.

Wielding his 9-iron with around 140 yards to the pin, he gouged the ball from the rough and sent it over the towering tree in his path. The shot came to rest at the back of the green, leaving a lengthy downhill putt for par.

A true champion, Nicklaus drained it to the delight of his adoring fans. He knew he had escaped disaster by the skin of his teeth, dropping down to his haunches in relief, and it proved to be a crucial moment as he opened up a four-shot lead over Australia's Bruce Crampton heading into the final round.

Nicklaus closed with a one-over-par 71, good enough to secure a two-shot victory over the Aussie and win his 14th of 18 major titles.

Nicklaus was being interviewed by 2002 PGA champion Rich Beem, who asked the great man: "How did Bob Rosburg not understand that you were Jack Nicklaus at this moment in time and you could do anything with a golf ball?"

The 86-year-old offered a cheeky reply. "Well, Rossy never asked me," he smiled.

It was a minor blemish in Rosburg's iconic broadcasting career, which spanned decades until his death aged 82 in 2009.