The birdie cheers echoed across rolling Firestone Country Club like tons of coal pouring down a distant chute today as Lanny Wadkins and Hale Irwin dueled each other in this World Series of Golf with avalanches of sound.

"You kept hearing roars from all around the course," said Wadkins, third round leader by a stroke at 69-66-67 - 202. "I felt like I was at Augusta. I was so pumped up I couldn't wait to pull the trigger and let 'er rip."

Irwin was on Wadkins' rear bumper all day like an Internal Revenuer on Thunder Road. As the pair hurled five birdies apiece in their cross-course battle, the rest of the field fired and fell back.

While Irwin blitzed the front nine with just 10 putts and finished with 32-33 -65 for the low round of the tournament and a 67-71-65 -203 total, Tom Weiskopf, the second-round coleader, fell into third place,four shots behind.

Again today it was Weiskopf's skittish temperament that derrailed him, this time at the ninth hole when he was tied with Wadkins for the lead and Irwin was just a phantom creeping up from the bottom of the leader board.

Weiskopf, the man with the best swing in golf, and the best ears, too, heard a camera shutter click 70 yards away and hooked an approach shot. "Who took that picture?" he snapped. Still garing, muttering at the crowd and ordering another photographer out of his line of sight, Weiskopf three-putted for bogey from 60 feet and gradually thereafter.

A wild drive at 18 and a final bogey for 72 left him tied with invisible man Mark Hayes for third at 207.

"I played terrible," fumed Weiskopf. "I'm glad I've only got one more day of this (golf season), then I can go hunting."

Weiskopf's penchant for seeing red and going blank-brained under pressure was a perfect contrast to the games of Wadkins and Irwin, two gritty players who make do with far less talent than Weiskopf.

Irwin tried to visit every chipmunk farm on the front nine as he missed five greens, but somehow whot three-under for the front. "It would be fair to say I turned a potential disaster into a big, big bonus," he said.

Irwin's strategy here is to play safe, try to hit every fairway and aim for the conservative fat part of every green.

But for five nervous holes on the front today his long irons deserted him and he repeatedly found himself in predicaments he managed to escape the way every duffer dreams he could. At the third, sixth and seventh holes he wedged up from the wiry fringe grass for "gimmes." At the fifth his sand shot stopped four feet short and he made the putt.

But the best came at the ninth where he hit "a 200-yard seven-iron out of a flyer lie in the rough," then chipped in for birdie from the fringe. That made three birdies including the chip-in, and four one-putt saves on the front side for 10 - count 'em - just 10 putts and a 32. That's why Irwin, an ex-college defensive back, is called a fair technical player with immense determination.

On the back Irwin hit every green, made two birdies and tried to "walk faster because my wife ordered me to get some zip in my step for TV."

Wadkins proudly offers himself as a strategic opposite to the conservative Irwin. "I just wanna rip at it and go. If anybody tried to slow down my swing or tell me to stop goin' for the par fives in two, just wouldn't listen. He, shootin's for the dern flags is what it's about. I'm out here to have fun and teach some a these big tough courses who's boss," he half-joked.

In three days Wadkins leads the tournament by far with 15 birdies - or "B's" as he calls them. And he has missed at least that many birdie putts inside 15 feet. "Be nice if I could putt," he said with a grin. At 18 today he had a 10-footer for birdie and "I was really grindin' on it. I lined it up four ways and three of 'em said it broke left. "Course it went straight."

Wadkins' one lapse came at the 17th tee after he had just rolled in a downhill 20-footer at the 575-yard monster 16th to take the lead for the first time alone.

Television people told the marshals to hold play for a commercial and Wadkins eyes narrowed as he and Hayes chi-chatted about what kind of varnish they used on their drivers.

When the go-ahead came, Wadkins lashed at the ball as though he wanted to drive the TV tower behind the 390-yard hole. He snap-hooked and growled. "That's what happen when you gotta wait."

But true to style, Wadkins fired for the pin from deep rough and almost ended up making another birdie.

Wadkins and Irwin can look forward to a head-to-head duel similar to one they had in Atlanta earlier this summer. Wodkins then led going to the last round by one shot, too,but finished with a 72, while Irwin won the tournament with a closing 68.

The two are friendly but know they come from different schools. Irwin is disciplined and mechanical with a pinched expression of peering concentration that looks a bit as though he might be nagged by a wife wanting him to walk faster.

Jack Nicklaus, playing with his most recent nemesis, Tom Watson, opened with three straight birdies to go one under par. He calmed down and shot 69 to hang in seventh place at 210, tied with Graham Marsh and one back or Ray Floyd and Gary Player. Watson, on his 25th birthday, losthis duel to Nicklaus today, 69-68.