Laura DeWald was angry with herself, sort of. If only she hadn't gotten sick, if only nature hadn't called, if only . . .

She might have done better than eighth. She might have gone under 2:30, something only four women in history have done in the marathon. "I think I must have done 10-minute miles for the last three," she sighed. "I even stopped and walked."

Life, of course, is full of 'only ifs.' But there was really nothing very iffy about DeWald's performance in the 85th Boston Marathon today. DeWald, a 23-year-old civil engineer from Arlington, Va., finished in 2:35.57, almost nine minutes faster than her previous best in the "adjusted" Marine Corps Marathon last fall.

"I was running with Phil Stewart (president of the D.C. Road Runner's Club). At 10 miles I saw our time: 54:40. I said, 'Are you sure you're right, Phil?' He said yes and I said, 'Oh my God.'"

DeWald, who was feeling and running relaxed, ran the first eight miles with the women's winner, Allison Roe. "She was so low key, it didn't seem like she wanted to push it," DeWald said. "She was just gliding along. With Patti (Catalano) you could see the determination written all over her face. Allison was looking around like she was just having a good time."

DeWald was in seventh place among the women until the 25th mile when she was passed by Nancy Conz of East Hampton, Mass. "She was really nice," said DeWald, who was feeling pretty sickly right then. "She said, 'Oh come on, you can do it, you're doing really well.'"

Indeed she was. DeWald placed higher among the women than any of the Washington-area runners did among the men. Terry L. Baker of Hagerstown, Md., was 36th in 2:16:49. Two other local runners, Henry Barksdale of Washington (45th place, 2:18:06) and Lou Patterson of Arlington (56th place, 2:19:18), finished below 2:20.

John R. Block, secretary of Agriculture, proved that the government can run efficiently. He finished in 3:06:49, 3,387th overall.

Craig Virgin, who finished second in the race, said, "I think those guys who finish in four and five hours have a lot of courage and guts, a lot more than those of us who finish in the top 10. We train harder and we're in better shape. They're out there all afternoon. It must be painful."