Highweighted Mister Brea, an Argentine-bred who had never won a major stakes race in the United States, captured the $85,650 John B. Campbell Handicap in the rain at Bowie yesterday.

Jockey Ruben Hernandez, providing a strong hand, moved Mister Brea into the lead down the backstretch and easily scored by 2 1/2 lengths over Ripon, last year's Campbell Winner.

Silent Cal was third, a neck behind Ripon.

Mister Brea, who covered the 1 1/4 miles in 2:04 3-5, was assigned 124 pounds by Racing Secretary Larry Abbundi. Some observers felt the weigh too high. But Mister Brea, who had done well in Argentina, rewarded his backers with a splendid effort.

His owner, Cayetana Diaz of Buenos Aires, earned $55,673.50 for her horse's victory.

The winner paid his backers in the crowd of 13,479 $5.80, $4.60 and $2.60.

Isella, winner of the Native Dancer two weeks ago, was a doubtful starter right up to post time. The 4-year- old had been injured slightly during a change of shoes earlier in the week and his trainer and owner were considering a withdrawal. Isella flashed some early speed but dropped out of it around the first turn, finishing last.

A heavy downpour coupled with high winds made the Bowie racing strip "sloppy" for the Campbell with the colours barely discernible as the field of eight was loaded into the gate. When starter Eddie Blind pushed the button it was Isella and Mister Brae breaking on top.

On the first turn Isella bore out and Ripon slipped through to take the lead under a stout hold. Mister Brea, known for a tendancy to bear in, was allowed to settle behind the field while saving ground.

Down the backstretch Hernandez urged Mister Brea into a contending position alongside Ripon. The pair coasted along to a 1:13 2/5 clocking for the six furlongs.

Turning for home Hernandez sent the winner to the front and dropped hims towards the rail. The 5-year-old responded to his waving of the whip left-handed and drew away. In the meanwhile Ripon and Silent Cal had their own private battle for the place position, with Ripon gaining the nod on the wire.

"I expected to go to the lead early," said Hernandez, "but when he didn't make it I waited until the backstretch to go for the lead. I let him roll from the seven-furlong pole."

A disappointed Mark Drury said of his mouth, Isella, "He wasn't striding right into the clubhouse turn and fell apart." CAPTION: Picture, Mister Brea with Ruben Hernandez aboard, easily wins the Campbell Handicap in a driving rain at Bowie. The winner's take in the $75,000-added race was $55,673.50. By Richard Darcey-The Washington Post