Big Day for Mitchell, Shula and Dolphins : AFC: Marino’s replacement passes for three touchdowns, coach ties NFL record for wins and team beats the Chiefs, 30-10. Montana is hurt.

Scott Mitchell passed for three touchdowns, and Don Shula caught George Halas.

Mitchell, making his second start in place of injured Dan Marino, gave the Miami Dolphins an early lead and the defense did the rest in a 30-10 victory over Kansas City as Shula tied Halas’ NFL record of 324 coaching wins.

“It’s nice to be part of it,” Mitchell said. “I know he’s excited about it. But I also know he would like to get to the Super Bowl, and that would make it even better.”

The victory improved Shula’s record to 324-152-6 (.678) in 31 seasons with the Dolphins and Baltimore Colts. Halas was 324-151-31 (.671) in 40 years with the Chicago Bears.

“The players have so much respect for him,” safety Louis Oliver said of Shula. “There’s so much professionalism in him. He wants to win so badly, and he instills that in you. He makes you want to play for him.”

Shula will have a chance to break the record next Sunday when Miami plays the New York Jets.

“It’s been a lot of years,” Shula said. “The important thing is the win--beating Kansas City.”

Joe Montana aggravated a strained left hamstring and departed in the second quarter with the Chiefs behind 13-0. He did not return, and his status for Kansas City’s next game Nov. 8 against Green Bay is uncertain.

The matchup was billed as a possible preview of the AFC championship game, but the Dolphins (6-1) easily won their fifth in a row.

“I’m not even the starting quarterback, and we’re still winning,” Mitchell said. “So we must have a pretty good team.”

Kansas City (5-2) lost for the first time in five games.

“We got our butts kicked all over Joe Robbie Stadium,” Coach Marty Schottenheimer said. “I did a lousy job, our staff did a lousy job, and our players did a lousy job. I think that says it all.”

Linebacker Bryan Cox led Miami’s defense with one forced fumble and two recoveries.

“We didn’t score every time; we didn’t stop them every time,” Cox said. “So it wasn’t perfect. But we played a great game.”

Cox’s jarring tackle caused running back Harvey Williams to fumble and left him motionless on the field for 15 minutes in the second quarter with a concussion. Williams was removed on a stretcher, taken to a hospital and held overnight for observation.

“Everybody on the sidelines was just hoping he was all right,” Chief receiver Willie Davis said.

Mitchell threw touchdown passes of 27 yards to Irving Fryar, eight yards to Keith Byars and 77 yards to Mark Ingram. Repeatedly fooling the NFL’s fourth-ranked defense, Mitchell completed 22 of 33 passes for 344 yards with no interceptions.

“I’m sure he’s caught a lot of people’s eyes,” Shula said. “I don’t know that you could give a team better quarterbacking and leadership than he’s given us.”