World-class distance runner Cathie Twomey of Athletics West fought off a challenge from Clemson's Terry Robinson and teammate Julie Shea on the final lap of the 3,000 meter run yesterday to win in a national best time of 9:03.75 in the Maryland Women's Open Invitational track and field meet at Byrd Stadium.

The 25-year-old former University of Minnesota miler, who broke her own meet record by .13 seconds, was running comfortably alongside Shea when Robinson sprinted ahead of both runners with just over 300 yards to go.

"She (Robinson) just suddenly took off past us," Twomey said. "I was a little surprised but I thought I'd better get going now or else."

Twomey swung wide passing her teammate before taking dead aim at Robinson. Just before the runners reached the final turn, the 5-foot-5 Twomey began sprinting and moved past Robinson and won by eight yards.

In the other feature distance race, Virginia's Aileen O'Connor went ahead early and lapped the other eight runners at least twice to easily capture the 10,000 meter run. With no one to push her in the last four laps, O'Connor jogged across the tape in a good time of 34:16.1, missing the meet record by almost three seconds.

Maryland's field specialist Marita Walton enjoyed a fine afternoon, hurling the discus 167-10, to break her own record by 3-6 1/2. Walton tied her shot record of 52-6 3/4.

Janet Dodson of Morgan State outran a good field in both the 100- and 200-meter finals to win in times of 11.93 and 24.56 respectively. Dodson anchored the Bears' victorious 440-yard relay team in 47.0.