Maryland's Ian Pyka added 10 1/2 inches to his lifetime best today and upset high school sensation Michael Carter in a rain-spattered shot put competition at the National Sports Festival.

In the high jump pit a few feet away, Olympian Paula Girven made it a double ration of gold for the Terrapins by edging Sharon Burrill on fewer misses as each cleared 6 feet 1 inch.

Tonight, as an overflow crowd of 7,300 looked on in the more comfortable atmosphere of the Air Force Academy Field House, another Marylander was decorated with gold. Gymnast Jackie Cassello of Silver Spring turned her concluding vault into a 9.9 masterpiece and a share of the vaulting gold with Christa Canary.

Pyka unloaded a throw of 65 feet 10 1/4 inches on his first attempt, before rain made things difficult for the field. Carter had additional problems, because his usual shot was ruled a half-ounce too light, and he could not reach 65 feet with various substituted.

"When they called my name, I just picked one off the ground and threw it," said Carter, who has a 16-pound best of 67-9 and earlier this year threw the 12-pound scholastic implement an unfathomable 81-3 1/2.

Rain also played a part in the discus, as Al Oerter passed on his final try and assured John Powell the victory. Powell threw 214 feet, the 42-year-old Oerter 211-8.

"The ring got slick when it started to rain and I have memories of a tremendous tear in my rib cage in 1960, just before Tokyo, while trying to throw in a wet ring," Oerter said. "I didn't want to go through that again."

Mike Roberson, Harvey Glance, Bill Collins and Mel Lattany gave the day's competition a bright start, before the thunderheads rolled in, by running history's fourth fastest 400-meter relay, 38.30 seconds.

Collins was a member of the U.S. World Cup team that set the world mark of 38.03 in 1977 and he said, "When we set the record, we had three or four weeks to train together. This team had just three days. I think we'd have gone faster with more time."

Collins hopes they will have the chance in the World Cup Montreal Aug. 26, saying, "I would suggest they take this team, if we can run the fastest in the world our first time out together."

In the most exciting race of the three-day track competition, Joetta Clark outstaggered Washington, D.C. native Robin Campbell in the 800 meters. Campbell led with 20 meters left but Clark slipped past to win in 2:05.5 as both women wobbled down the stretch like drunken sailors struggling to get back to their ship.

"i couldn't see the finish line 10 or 15 yards away," said Campbell, running at altitude for the first time. "The finish kept coming close and going back.I kept drifting out and we bumped a few times. I was numb afterward, like prickly heat over."

Campbell was scheduled to run in the 1,600-meter relay later and said, "I wanted to run, but a doctor said I couldn't because he didn't want to ship me home in a box."

Clark and Evans White spoiled the engagement announcement of Susan Vigil and Mark Belger, who had hoped to celebrate with a victory lap.

Vigil was seventh in the women's 800 and Belger placed third in the men's version, as White (1:48.88) and Jack McIntosh overhauled him in the stretch.

James Sanford won the 200 meters in an eased-up 20.64 as John Christian of D.C International grabbed second in 20.91. Dwayne Evans, the National AAU champion, pulled a muscle on the turn and could miss the World Cup.

Willie Banks' holdover wind-aided triple jump of Sunday, 56-10 1/2, won that event, although Tommy Haynes challenged today with 56-1. CAPTION: Picture, Runner-up Robin Campbell is supine and winner Joetta Clark gasps for breath after the 800-meter run at the National Sports Festival. It was an exhausting experience running at the 7,000-plus-foot altitude. UPI