It's something the San Francisco 49ers have known well for half a decade.

The Super Bowl champion Giants (4-1) will try to forget their first regular-season loss since Dec. 29 when they face the reeling 49ers (2-4) at Giants Stadium on Sunday.

New York was battered and bruised by the Cleveland Browns in a nationally televised 35-14 loss on Monday night that ended its eight-game winning streak and 11-game road run - 12 including the Super Bowl. The Niners have lost three straight in what has all the appearances of a sixth straight losing season.

"You know what, the taste (of defeat) is still there," Giants halfback Brandon Jacobs said. "We know what we have to do. We know how this league is. It's dog eat dog. If we come out looking like we did on Monday night, San Francisco is going to hit us in the chin."

The Browns delivered a knockout punch. They gained 454 yards in total offense and effectively prevented the Giants from getting anywhere near quarterback Derek Anderson. Cleveland also pressured Eli Manning, bruised his chest and forced three interceptions, including one returned for a clinching fourth-quarter touchdown.

"You remember this more than when you come in after a win," guard Chris Snee said. "It's definitely different. You look on what part you played in letting the team down and you learn from that."

The 49ers are obviously slow learners. They have not had a winning season since 2002, and they are making way too many mistakes already this year.

While they are scoring a lot more under new offensive coordinator Mike Martz, they also has given up a league-high 167 points, including at least 30 in each of the last three games.

"We have had spurts where we have played well and then we have been inconsistent at times," coach Mike Nolan said. "We gave up some explosive passes a few weeks ago that cost us the game."

In last week's 40-26 loss to the Philadelphia Eagles, San Francisco took a 26-17 lead late in the third quarter and then fell apart in the final quarter. It was outscored 23-0, with the Eagles' final score coming on an interception return.

"It is very frustrating," 49ers halfback Frank Gore said. "The reason why I am so frustrated is because it isn't like we get out there and get whooped-up and teams are burying us. It is just that we, as a team, are not executing. It is just frustrating because I know we are a good team. That is what makes it so frustrating."

If there is a positive for the 49ers, the Giants showed more than a few weaknesses in the loss to Cleveland.

The defense, which recorded 13 sacks in the first three games, didn't have any against the Browns. The front seven barely touched the Cleveland quarterback and allowed the Browns to run for 144 yards.

The Giants also have problems with injuries on defense. Middle linebacker Antonio Pierce has been bothered by a quad injury for more than a week. Weakside linebacker Gerris Wilkinson sprained a knee on Monday night and is not expected to play.

Rookie Bryan Kehl has split time with Wilkinson and is the logical choice to replace him. Coach Tom Coughlin also might opt to use a safety in the box playing against a West Coast offense. In that case, either Sammy Knight or rookie Kenny Phillips would play more.

The Giants' offensive line had a little trouble picking up the blitz Monday, and Manning was under pressure more than in the first four games. The Super Bowl MVP bruised his chest when 350-pound tackle Shaun Rogers drove him into the ground after a pass.

"We just have to get back to our style of football, and that is being aggressive, being physical, being smart," said Manning, who left no doubt he will play. "They are a good team and they do some good stuff on defense, so it is a matter of just playing smart, but making plays when they are there."

The Giants should get a lift knowing this is basically the same team they beat 33-15 last season, getting six sacks and forcing four turnovers that led to 24 points.

"They dominated us," Nolan said. "I thought they were more physical on both lines of scrimmage. Their ends did a great job. They had a sack. They had one for a fumble touchdown. They got field position due to some turnovers. I thought they whipped our tail last year, to be honest with you."

Coincidentally, that's the way the Giants felt after being beaten by Cleveland.

"It was not a feeling of not knowing how I felt, it was just a feeling of knowing we didn't play Giants football," defensive end Justin Tuck said. "If we would have gone out there and played our style of football and they would have beaten us that would have been a different story, and I would not have been so down. We just didn't play well."