The Cosmos cranked up their $6 million offense in the second half and inflicted a 6-1 slaughter on the dazed and groggy Washington Diplomats yesterday before 47,700 ecstatic fans at Giants Stadium.

Cosmos striker Giorgio Chinaglia had a field day, finding the cracks in the Dips defense to score three goals, all in the second half. Dennis Tueart, Terry Garbett and Franz Beckenbauer also scored for the talent-rich Cosmos, the league leaders in every-offensive department.

The Cosmos, in winning their sixth straight game and 20th consecutive on the AstroTurf surface here, yielded the game's first goal but otherwise toyed with their Eastern Division rivals throughout the first 45 minutes.

The defending North American Soccer League champions outshot Washington, 14-5 in the first half but missed countless opportunities. The most glaring error was a missed penalty kick by the NASL's leading scorer, Chinaglia.

The score was tied, 1-1 when Carmen Marcantonio was called for pushing the speedy Tueart in the penalty area. Chinaglia, who predicted he would score 30 goals this season, received a hearty round of boos as his free 12-yarded dribbled wide to the right.

"I make mistakes too," said a happy Chinaglia. "We just played very well in the second half. We began to run and create."

When the Cosmos press they can be devastating, as Cosmos goalie Jack Brand verified.

"I used to be against them so I know how they can kill you said Brand, who played in Rochester last year. "Once the Cosmos get the lead, that's trouble for the other team. I have some team in front of me so I didn't have much to do. I didn't get much of a test."

Brand, playing in place of regular goalkeeper Erol Yasin, recorded only two saves while Washington's Bill Irwin managed to stop eight missiles.

The Washington net man must have felt like a sitting duck in a shooting gallery in the final 33 minutes when the Cosmos began their assault.

Garbett took a nice crossing pass from Gary Etherington, a former All-Met player from Mount Vernon High School and pressed into action because of the suspension of Steve Hunt, and booted in the go-ahead goal at 57:36.

"That goal was the one. But even after-that, I felt we could come back and win," said Washington Coach Gordon Bradley. "But that second goal forced us to throw everything forward, leaving ourselves open a bit in the back."

And the Cosmos, who have scored five or more goals six times this season and have 53 goals for the season, took advantage of Washington's tiring defensive unit.

"They kept coming. We lost a bit of our composure and they kept the pressure up," said Irwin.

Chinaglia got away from Mike Dillon and handled a soft [WORD ILLEGIBLE] from defender Robert Iarusci and sent a low 18-yard rocket just under Irwin's desperate dive for a 3-1 Cosmos lead at 69:15.

Washington had not surrendered more than three goals in a game this season but the Cosmos owned a 4-3 lifetime edge over Washington going into this season, including wins by scores of 5-0, 9-2, and 8-2.

Beckenbauer, got into the scoring act by sending a hard liner that sailed over Irwin's head just under the ossbar to put the Cosmos ahead 4-1, at 73:07.

"I told my players at the half when the score was tied, 1-1, to go out and speed up play," said Cosmos Coach Eddie Firmani. "I didn't think they could keep up with our wingers. I knew they would cause them a lot of trouble."

Tueart was giving defender Tommy O'Hara the blues on one side while on the other side Etherington worked on Ane Mihalovic, who suffered a leg injury early in the game, and his replacement, Randy Garber.

Chinaglia simply waited until his wringers beat their men and raced into the middle to look for the crossing passes. His second and third goals came five minutes apart and left Giants Stadium rocking and the Washington defenders shaking their heads in dismay.