Disabled golfer Casey Martin has a legal right to ride in a golf cart between shots at PGA Tour events, the Supreme Court said Tuesday.

In a 7-2 ruling with implications for other pro sports, the justices ruled that a federal disability-bias law requires the pro golf tour to waive its requirement that players walk the course during tournaments.

"We have no doubt that allowing Martin to use a golf cart would not fundamentally alter the nature" of the PGA Tour's tournaments," Justice John Paul Stevens wrote in the majority opinion.

He said the purpose of the tour's walking rule is to introduce fatigue as a factor that could influence the outcome.

But Stevens said Martin's circulatory disorder, which obstructs blood flow to his right leg and heart, causes him greater fatigue even with a cart than is experienced by competitors who walk.

When Congress passed the anti-discrimination law for the disabled, lawmakers intended that sponsoring organizations "carefully weigh" the effect of their rules on the disabled, Stevens said.

Granting an exception would "allow Martin the chance to qualify for and compete" in events also open to qualifying members of the public, he wrote.

Justice Antonin Scalia wrote the dissent, joined by fellow conservative Justice Clarence Thomas.

"In my view today's opinion exercises a benevolent compassion that the law does not place it within our power to impose," he said.

Scalia wrote that for the majority, "there is one set of rules that is fair with respect to the able-bodied, but individualized rules ... for talented but disabled athletes." He said the law "mandates no such ridiculous thing."

The 1990 Americans with Disabilities Act bans discrimination against the disabled in public accommodations, including golf courses and entertainment sites. The law requires "reasonable modifications" for disabled people unless such changes would fundamentally alter the place or event.

That law applies to professional sports events when they are held at places of public accommodation, the justices said.

The decision upholds a lower court ruling that ordered the PGA Tour to let Martin use a cart. The lower court said using a cart would not give him an unfair advantage over his competitors.

Martin has a circulatory disorder in his right leg called Klippel-Trenaunay-Weber Syndrome that makes it painful for him to walk long distances. He sued the PGA Tour in 1997, saying the ADA -- enacted in 1990 -- gave him a right to use a cart during tour events.

On Jan. 19, 2000, Martin became the fist PGA Tour member to use a cart in competition. He shot a 4-under-par 68 in the first round of the Bob Hope Classic but wound up missing the cut by three strokes.

Last December, on the final day of a qualifying tournament, Martin fell one stroke short of regaining his PGA Tour card. He has full status on the Buy.com Tour.

Martin was a teammate of Tiger Woods at Stanford University, and the two used to room together on road trips. Woods has said that Martin sometimes would be in so much pain that he couldn't get up to use the bathroom.

Jack Nicklaus and Arnold Palmer have spoken against allowing any player to use a cart in elite competition to accommodate a disability. They have said that using a cart would give Martin an advantage and take away a basic part of the game: the ability to walk an 18-hole course.

The San Francisco-based 9th U.S. Circuit Court of Appeals ruled for Martin in March 2000. But the next day a Chicago-based federal appeals court ruled against Indiana golfer Ford Olinger, who sued the U.S. Golf Association for the right to use a cart in U.S. Open qualifying. The appeals court said a cart would change the nature of competition. Among those supporting the PGA Tour in friend-of-the-court briefs were the Ladies Professional Golf Association and the men's pro tennis organization, the ATP Tour.

The Justice Department backed Martin, as did disability-rights groups including the National Association of Protection and Advocacy Systems and the Disability Rights Education and Defense Fund.

The case is PGA Tour v. Martin, 00-24.