By Vinnie Perrone Washington Post Staff Writer

Chas' Whim came from nowhere to win the Congressional Handicap yesterday at Laurel.

The resolute 3-year-old apparently led throughout the 1 1/4-mile race, but no visual documentation was available. Dense fog paid an unwelcome visit to Laurel and stayed for all 11 races, severely limiting visibility for everyone but horse and jockey.

From the grandstand, the backstretch was as revealing as a blank movie screen, the infield tote-board at times barely distinguishable. By the last race, the sixteenth-mile pole could hardly be seen from the finish line 110 yards away.

Races that begin on the backstretch were condensed to about 13 seconds, the time it took horses to emerge from the mist for the final furlong. That did little to curtail betting, however, as 12,474 fans risked more than $2 million.

Track announcer John Curran was resigned to calling what little action he could from a television monitor, but even that provided little aid. "On the outside, Paparatius takes the lead," he announced as the third race began. "After that, your guess is as good as mine."

A short time later, Curran descended from his booth and said, "I'm thinking about going to lunch. Nobody will notice."

While observers strained, jockeys said the fog posed little problem. "We can see about an eighth of a mile," said Donnie Miller Jr. "It's not so good for the public, but it's okay for us."

The conditions caused trainer Rodger Gill undue consternation. Curran had not picked up Chas' Whim well into the stretch, and Gill, standing on an outdoor bench, became worried when he heard no mention of his horse. "I thought he was beat," he said.

Chas' Whim then came charging into the clear under the red-silked Allen Stacy, and Gill witnessed the final fragments of a 1 3/4-length victory over Jet Stream. Reputed Testamony closed fastest of all to finish third, less than a length behind Jet Stream.

Chas' Whim's fifth stakes victory of 1990 and ninth overall followed an uncharacteristic defeat in the Annapolis Handicap, when he finished fourth and was disqualified as a heavy favorite under a career-high 124 pounds. Shouldering five fewer pounds yesterday, Chas' Whim missed the 1 1/4-mile track record by a fifth of a second. His time of 2:01 4/5 matched that of 1989 Congressional winner Learned Jake, who was sixth in a seven-horse field yesterday.

Seattle Dawn, the only female in the lineup, pressured Chas' Whim into a fast quarter-mile of :23 1/5 before they slipped out of sight. Stacy said Chas' Whim pulled ahead early into the backstretch, and there the fractions slowed. When track cameras caught the field at the far turn, Chas' Whim had a short lead over Jet Stream, while Michael Hunter -- in his last mount before leaving for Florida -- whipped favored Runaway Stream near the rail. By the time he next appeared with about a furlong remaining, Chas' Whim had a three-length lead.

Now, it looks as though he'll disappear again. Gill said Chas' Whim will return home to Elmer and Harriet Heubeck's Hobeau Farm in Florida for a few months's rest.

Gill said they had accepted a $200,000 offer for Chas' Whim earlier this year, but the deal was killed when X-rays revealed a knee chip. With yesterday's win, Chas' Whim has made $299,641.