SAN FRANCISCO — The end result was another disaster. But the Mike Singletary era is already a 100 percent U-turn from the Mike Nolan era.

Accountability. Honesty. Action.

On Sunday Singletary, in order: 1. benched J.T. O'Sullivan, who was having another disastrous performance. 2. sent Vernon Davis off the field for acting like an idiot. 3. apologized for the team's performance.

After three-plus seasons of window dressing, blather and finger-pointing it was startling.

If anyone thought the 49ers were going to vastly improve in one week, that was crazy. But if anyone was concerned that the coaching change was just going to be a case of slipping a Hall of Famer into the head coaching suit, we found out right away that wasn't the case.

In an embarrassing, potentially season-finishing 34-13 loss to awful Seattle, Singletary showed that he is not going to just sit back and spout platitudes and cliches. That he's not going to pretend everything is fine while his team is collapsing around him. That he's not going to blame the players and absolve himself.

"Before you ask any questions I want to say this," Singletary said when he entered the post-game press conference. "Number one, I apologize. I apologize for the start."

The Mike Singletary era has lasted for exactly 60 minutes of football, but it already has a defining moment, something you'd be hard pressed to find in the previous regime. With 49 seconds left in the third quarter, Davis caught a pass. At the end of the play he had words with defender Brian Russell and reached out — right in front of the official — and slapped Russell on the facemask. He was flagged for unnecessary roughness, wiping out the gain and putting the 49ers in a second-and-18 hole.

Singletary yanked him off the field. When Davis came off he headed toward Singletary then tried to run a 10-yard out to avoid the coach, who walked down the sideline to meet him with angry words. Davis met with the classic teenager pose — arms outstretched, mouthing "What? What?"

Davis went to the bench. Singletary also went there for more words. A few minutes later Singletary sent Davis to the locker room. Davis headed off and Singletary yelled at him to come back and get his helmet.

"I will not tolerate players that think it's about them," Singletary said. "We cannot make decisions that cost the team and then come off to the sideline and be nonchalant.

"I'd rather play with 10 people and just get penalized, rather than play with 11 when I know that right now that person is not sold out to be part of this team.

"I told him that he would do a better job for us right now taking a shower and coming back and watching the game than going out on the field."

When Davis tried to talk to him after the game, Singletary said, "Vernon, you don't want to talk to me right now. You don't."

Most coaches would say it was between the player and the coach, a misunderstanding, a blah-blah-blah. Singletary was mad. He was honest. He failed to be fluffy.

At the end of the second quarter Singletary made the call to yank O'Sullivan. The quarterback, who is in descending spiral of awfulness, fumbled on the 49ers' first drive. He turned the ball over twice more — leading to 10 Seattle points — and was sacked three times. The crowd had turned on him. Singletary had seen enough.

He told Mike Martz he wanted to put in Shaun Hill. Martz — an emphatic supporter of O'Sullivan didn't argue.

"I think Mike knows me enough right now, going through this week, that we didn't have to talk about it," Singletary said.

After one game, we all know something about Singletary. He's a real change.