The San Diego Chargers scored 24 points in the first half tonight as quarterback Dan Fouts riddled the Dallas Cowboy defense for 240 yards. They got a touchdown on an immaculate reception, second perhaps only to Franco Harris' 1972 miracle. They chased Danny White out of his pocket all night, sacking him five times. They accumulated more than 400 yards in offense.

They lost, 42-31.

There were two main reasons for the Charger demise: Danny White and the Chargers. White scrambled away from the San Diego defense time and again, picked the secondary clean and hit three touchdown passes. The Chargers helped set that up by turning the ball over six straight times in the second half, twice on fumbles after long gains, once on a fumble at their own 20 and three times on Fouts interceptions.

It all added up to a stunning, runaway romp for the cowboys in a 3 1/2-hour donnybrook that started out to be a Charger rout. Instead, the Cowboys now are 6-2, one game behind the Phildelphia Eagles in the National Conference East. San Diego is 5-3 and tied for the lead in the AFC West with Oakland.

Trailing, 24-14, at the half, the Cowboys scored the first three times they touched the ball, twice on short dives by Timmy Newsome, then on a 12-yard White to Jay Saldi pass -- on a play where the primary receiver fell down. Then the defense did its job and most in the exhausted crowd went home happy.

All this with Tony Dorsett watching from the sidelines with bruised ribs and what's his name, No. 12, sitting in a comfortable seat in the stands.

The game started tamely enough with the Chargers taking the opening kickoff, moving from their own 41 to the Dallas 28, bogging down and getting a 45-yard field goal from Rolf Benirschke (his 11th in 15 attempts) for a 3-0 lead 2:17 into the game.

Minutes later, with the Chargers on the Cowboy 41, Fouts badly underthrew John Floyd on a turnout route. Steve Wilson, the second-year cornerback from Howard, stepped in front of Floyd and would have gone 72 yards down the sideline for a touchdown if Mike Thomas -- yes that Mike Thomas -- hadn't knocked him out of bounds on the San Diego 35.

Given that boost, White quickly took advantage. He hit Billy Joe Dupree for 15 yards. Then Ron Springs dashed 18 yards to the two. He was called for face-masking when he tried to straight-arm safety Mike Fuller, putting the ball on the seven. Two plays later, Springs went through a huge hole in the left side of the Dallas line from four yards out and with 1:58 left in the quarter it was 7-3 Dallas.

Tame stuff. But the evening was young.

Early in the second quarter, the Chargers faced first and 15 on their own 42. Back went Fouts, throwing to Charlie Joiner cutting across the middle at the Dallas 48. As Joiner went up he was crashed into by Wilson. The ball bounced off Joiner's hands and off Wilson's helmet. It flew threw the air right into the hands of John Jefferson who was gone, 58 yards in a play that could have been labled Immaculate Reception II. It was 10-7, Chargers.

Not for long. On the Cowboy's next series, White went into the shotgun on third and 13 from the eight. He had running back James Jones open but badly underthrew the ball. Linebacker Woody Lowe stepped in, deflected the ball, caught it with his right hand, then jogged 16 yards into the end zone for a 17-7 lead with 8:30 left.

White quickly took the Cowboys 75 yards, using 12 plays, converting three third downs on the way. The last of those was a 17-yard pass on third and 10 to a diving, wide-open Butch Johnson in the end zone.

It took Fouts five plays and 80 seconds to get the touchdown back. The key plays were a 33-yard strike to Joiner over the middle which put the ball on the 10 and a touchdown pass from there to a wide-open Kellen Winslow for a 24-14 lead.

The Cowboys tried to come back. White hit Dupree over the middle at midfield. The big tightend looked up field and saw Ray Preston coming at him. DuPree threw a vicious elbow and succeeded only in losing the ball. Pete Shaw recovered for the Chargers and with 27 seconds left the Chargers had a chance for still more. They got as far as the 29 before Fouts -- 14 of 23 for 240 yards for the half -- missed twice. Then Benirschke was wide right.

The Cowboys needed four minutes to get the deficit to three after taking the second-half kickoff. Again, a weird play intervened. With first down on the Charger 10, White dropped the snap. Normally that is disaster. This time, tight end Saldi, in motion toward White, scooped up the loose ball and went eight yards to the two. Two plays later, Newsome was in the end zone and it was 24-21 with a long way to go.

The Cowboys were just warming up. On their next series they used a fake White punt (his second of the night) to turn a fourth and 11 at the 39 to a first and 10 at the San Diego 34 when Frank Duncan hit White late after his 12-yard scramble. Four players later Newsome plunged in again and and the Cowboys were in front, 28-24.

The Chargers immediately moved the ball again. But Muncie fumbled at the Dallas 48 after an 18-yard gain on one possession and Winslow incredibly fumbled at the Dallas 20 after a juggling 43-yard catch. Both times the Cowboys recovered.