Chargers Shut Door on Chiefs : AFC: San Diego holds Kansas City to only 61 yards rushing while Butts gets 119, including a touchdown.

Quarterback Stan Humphries ran off the field holding his helmet triumphantly above his head with his good arm.

Linebacker Junior Seau tossed his gloves into the stands, while linebacker Gary Plummer found a TV camera and shouted: “Isn’t this unbelievable? There is no stopping us now.”

After opening the season 0-4, the San Diego Chargers have won 12 of 13 games and are within two victories of advancing to the Super Bowl for the first time in franchise history.

The Chargers ended a six-game losing streak against the Kansas City Chiefs, 17-0, Saturday in a first-round AFC playoff game before 58,278 fans at San Diego Jack Murphy Stadium.

It was the first shutout in a non-strike game against Kansas City (10-7) since 1987.

“This is my seventh year here and we haven’t even smelled the playoffs before,” defensive end Leslie O’Neal said. “Now that I’ve had a taste of it, I’m hungry and I want to keep going.”

The Chargers (12-5) will play the Dolphins in Miami (11-5) next Sunday.

“We’re young,” said Seau, who was 12 the last time the Chargers were in the playoffs. “But we are a great team, and when we play as a team, I don’t think anyone can stop us. When I first came here three years ago, we had more people in the stands rooting for the Chiefs. Now it’s totally different.

“The turnaround in San Diego has been fantastic.”

After a scoreless first half, the Chargers went ahead during the third quarter on Marion Butts’ 54-yard touchdown run, the longest rush of his career. Butts, a seventh-round draft pick who spent much of his career at Florida State blocking for Sammie Smith, now a Denver Bronco, finished with 119 yards in 15 carries.

“He’s one of the hardest working guys on our football team,” Coach Bobby Ross said. “I’m really happy for Buttsy. He’s a guy that’s been banged up all year, but he’s hung in there.”

Butts suffered a knee injury during a season-opening loss to Kansas City and the knee was hurt again during another loss to the Chiefs in early November. He accused the Chiefs of intentionally trying to hurt him after their second game.

Saturday, he paid them back. On a run reminiscent of his third carry in the NFL, a 50-yard touchdown against the Raiders, Butts followed the block of tight end Alfred Pupunu, ignored the arm-tackle attempt of safety Charles Mincy and outraced cornerback Albert Lewis to the end zone.

“I’m not fast,” Butts said with a smile, “but I have satisfactory speed when I’m being chased.”

On the Chiefs’ next possession, Charger tackle Blaise Winter tipped a pass by Dave Krieg high into the air, and it was intercepted by O’Neal.

“It’s been a long time since I got an interception (1986),” said O’Neal, who had two sacks. “We made some big plays, and things just started to snowball for us.”

O’Neal’s interception gave the Chargers the ball at the Chiefs’ 26-yard line and set up John Carney’s 34-yard field goal, which gave San Diego a 10-0 lead.

The Chiefs’ offense, meanwhile, continued to misfire. In the second half, the Chiefs came no closer to the goal line than the Chargers’ 43-yard line. They finished with only 61 yards in 19 carries.

“We had to step up and score some points, and we didn’t,” Kansas City linebacker Derrick Thomas said.

While the Chiefs continued to stumble, the Chargers sealed the victory with a 91-yard drive during the fourth quarter.

Linebacker Steve Hendrickson, who doubles as a blocking fullback, carried the ball for the first time this season and scored on a five-yard run up the middle with 4:57 to play.

“Coming from an 0-4 start to make the playoffs was (making) history,” Plummer said. “Winning the division was history. The team is making history. Teams that run the ball well and play good defense win playoff games.”

The Chargers also have been successful because of the development of Humphries, who had five starts in his career in Washington before being traded to San Diego during training camp.

Humphries, 12-4 as the Chargers’ starting quarterback, suffered a dislocated shoulder a week ago in Seattle but did not miss any practice time this past week.

“It was obvious he was in pain at times out there,” Charger tackle Harry Swayne said. “But he hung in there, and I think he showed us something.”

Humphries wore additional padding to protect his injured shoulder, but it did not appear to affect his play. He completed 14 of 23 passes for 199 yards, and pronounced himself fit after being sacked five times.

“It held up well,” Humphries said. “There was some pain, but it really didn’t bother me. It feels great now . . . winning helps.”

AFC Notes

The Chargers lost running back Rod Bernstine 53 seconds into the game because of a sprained left ankle. . . . The Chiefs’ Christian Okoye had no carries and Barry Word had only two. . . . John Carney’s 52-yard field-goal attempt hit the crossbar in the final minute of the first half and ended a streak of 16 successful kicks. . . . The Chargers will return to San Diego Jack Murphy Stadium for the AFC Championship game if they defeat Miami and Pittsburgh loses next week.