Jackie Joyner-Kersee and Florence Griffith Joyner share the distinction of being world record-holders. Joyner-Kersee, however, knows she's the best in the world, while Griffith-Joyner is just beginning to realize she can be the best.

The sisters-in-law entered the record book together Saturday when they produced historic performances in the U.S. Olympic Track and Field Trials.Griffith Joyner clocked 10.49 seconds to smash the world record in the women's 100 meters, and Joyner-Kersee reaffirmed her claim to the title of track and field's greatest female athlete when she scored 7,215 points to set her third world heptathlon record in three years.

Carl Lewis and Willie Banks also turned in landmark performances to highlight the second day of competition.

And former BYU runner Julie Jenkins finished second in her 800-meters heat with a time of 2:04:04.

Griffith Joyner bettered the previous world record of 10.76 run by Olympic champion Evelyn Ashford Aug. 22, 1984 at Zurich, Switzerland. She will run in the 100 semifinals and final Sunday.

The 28-year-old from Los Angeles has been more productive at 200 meters than 100, but her time confirms her status as one of the world's top sprinters.

"I can't believe the time - 10.49," said Griffith Joyner, a 200 meters silver medalist in the 1987 World Championships. "I didn't think it was possible today. I'm definitely going to try to do even better tomorrow. I can't predict a time. Nobody even considers me being a 100 runner, but I said I would try."

Joyner-Kersee broke her previous record of 7,158 established Aug. 1-2, 1986 in the U.S. Olympic Sports Festival at Houston. She set her other record of 7,148 one month earlier in the Goodwill Games at Moscow.

The 26-year-old UCLA graduate from Long Beach, Calif., owns the five highest totals for the heptathlon, a seven-event competition contested over a two-day period.

She entered the final event, the 800 meters, needing to run at least 2 minutes, 24.95 seconds to break the record. Joyner-Kersee, who will be the overwhelming favorite in the Summer Olympics Games at Seoul, South Korea, finished well under that time in 2:20.70.

"I feel very happy, very pleased with my performance, but when I go to Seoul, I'll be very motivated to go

for the gold," Joyner-Kersee said.