Could there be any boxing enthusiast in the land who wasn't on his feet for the furious, bittersweet 15th round of Wednesday night's heavyweight championship fight in Las Vegas?

This was what live sports on televsion is all about. A heavyweight crown changing heads is always a compelling spectacle, and during that last round, the longest three minutes imaginable, the tube took us close enough to ringside to smell the smoke and the sweat and the blood.

That part of the millions of us who cannot resist a hopelwss underdog's fantasies coming true soared with Leon Spinks. And at the same time our limbs and sentiments ached with Muhammad Ali, engulfed by fatigue - a magnificent campion battling on after his enormous gifts and energy had deserted him. Even his detractors can no longer condemn his immense pride as unseemly hubris.

"My heart is bleeding for Ali. He could put this kid away, and he does not have it at age 36 to come get him,"sighed Dr. Ferdy Pacheco as the final minute of Ali's reign fled. After so many battles in the champion's corner, Pacheco was an inside outsider as CBS-TV's ringside analyst. But he wore that bleeding heart on his sleeve becomingly, eloquently.

Ali had staggered Spinks with a good right hand, and momentarily liiked as if he might put him away.

But he was too spent, too weary, to produce the kind of closing flurry he did against Earnie Shavers his last time out.

As Pacheco noted later, over a replay of the final round "If you'll follow the round, Spinks was exhausted and finished, but so was Ali. He paid the price finally of being 36 years if age. Had this been last year, when he still had the gas, he would have come on like he did with Shavers and finished him!"

After that brief flash of rekindled hope, Pacheco sensed that Ali's arms were too leaden to permit the redeeming spurt he so desperately needed and yearned for. The king was dying on his feet, and the longtime friend and physician to the royal court had his finger on the pulse. At the end sorrowfully but with enough professional detacment to satisfy a situation in which it was impossible for him to be dispassionate, he pronounced Ali defeated.

There was unbearable tension as the decision was read, the ring announcer having revealed that it was a splot decision, but no real doubt as to the outcome.

The TV audience sensed, as did the live crowd and both corners surely knew deep down, that Spriks had won. The 24 year old former Marine and Olympic gold medalist, with barely enough pro experience to qualify him as a reasonable sparring partner for Ali, had accomplished what few thought possible. Widely denounced as one of the great mismatches in boxing history, this bout had become one of its most stunning upsets.

The verdict confirmed Sprinks and his handlers erupted int an instant replay of the jubilation they had displayed spontaneously at the closing bell. Ali's entourage was subdued, baleful, shocked and hurt. The closeups on the screen, so graphic, so poingnant, needed no words to amplify them.

We could have done quite nicely without Brent Musburger's comments at that point, and certainly without interviewer Bob Halloran - who certified himself throughout the evenign as a real lightweight, and a rank amateur to boot.

On an evenign with meaningful, obvious questions to be asked - we wanted to know about tye rumblings of discontent within Ali's camp, about remored friction between the champ and Black Muslim leaders, about Ali's uncharacteristic prefight silence that turned this title bout into Spinks vs the Sphinx - Halloran gave us pablum interviews, conducted with all the artfulness of an obnoxious baby drooling.

The color commentary by three knowledgeable and distinctive experts - street wise Angelo Dundee and Gil Clancy, and the articulate Dr. Pacheco - was constantly first rates. CBS's professional voices, Musburger, Tim Ryn and especially Halloran, let us down.

But little matter, TV is a visual medium to which boxing lads itself perfectly. The video side of CBS's presentation was superb. Paudits to director Frank CHirkinian, who chose his camera angles flawlessly, stayed on top of the action and made judicious use of a reveling overhead camera.

From the shots of Ali shadowboxing in front of a mirror in his dressing room befor the fight marred only by more Halloran's inane babbling - to the wise decision not to cut away from the mob scene in the ring at the final bell for a planned station break, the camerawork and visual coverage were splendid.