For the first time in club history, the Jets improved to 5-0 yesterday, but it wasn’t easy. At halftime, the Jets headed for the locker room trailing 14-3, having been thoroughly outplayed by a San Francisco team that had lost four of its first five games.

The Jets were forced to play a lot of man-to-man coverage against San Francisco’s three-receiver sets, and that proved problematic. New York’s defensive line did not do a good job of getting pressure on 49ers QB Tim Rattay, and he took ad vantage of the time he had to find receivers down the field. He opened the scoring with a 33-yard pass to Brandon Lloyd. In the second quarter, Rattay threw a 65-yard pass to Arnaz Battle that set up Kevan Barlow’s 2-yard run for the Niners second touchdown.

The Jets’ offense didn’t fare much better, managing just a field goal on six first half possessions. Tackle Jason Fabini was having a difficult time containing San Francisco’s quick outside pass rushers. Both starting guards (Pete Kendall and Brandon Moore) were inactive because of injuries, and the Jets weren’t able to control the line of scrimmage in the first half.

Good teams make adjustments, and the Jets came out with much more intensity in the second half and took control of the game. Defensive coordinator Donnie Henderson left the coach’s booth and went down to the Jets sideline to rally his troops. Rattay was sacked three times in the second half and completed only one pass longer than 10 yards. Two of those sacks came from John Abraham, giving him an AFC leading seven for the season.

The Jets offense reclaimed the momentum on their first possession of the second half. Tight end Anthony Becht made two tough catches for first downs. LaMont Jordan, who had carried the ball just once in the Jets’ first four games, looked impressive while spelling Curtis Martin. On third-and-five, Jordan made a 6-yard catch for a first down. On the next play, he bowled over cornerback Shawntae Spencer for an 8-yard gain, then capped the drive with a hard-charging 17-yard touchdown run.

Jordan’s score was the first of three rushing touchdowns for the Jets in the second half. The burst of energy that Jordan supplied should lead to his getting more playing time in the coming weeks. The Jets need Martin to stay healthy and must avoid overworking him if they hope to make a playoff run.

The defense stiffened to protect a slim 1-point lead in the fourth quarter. An Abraham sack forced a fumble that killed one drive, and rookie Jonathan Vilma intercepted a Rattay pass with less than two minutes left that sealed the victory.

***

For the third consecutive week, Curtis Martin moved up one spot on the all-time rushing list. With 111 yards against the Niners, he moved past Marcus Allen into eighth place. Martin now has 12,282 career rushing yards and needs just 30 more to move past Jim Brown for seventh place and 135 to surpass Jerome Bettis and claim sixth.

With a league-leading 613 rushing yards this season, Martin has provided a ground threat that has helped Chad Pennington complete more than 70% of his passes. When defenses bring players up to the line of scrimmage to contain Martin, they’re susceptible to the quick short passes on which the West Coast offense is based.

***

Next up for the Jets are the New England Patriots, who extended their consecutive win streak to 20 games against the Seahawks yesterday. The Boston-New York rivalry is not as intense for football as it is for baseball, but next Sunday’s matchup will be a huge game that will help determine the balance of power in the AFC. two games the Jets and Patriots play head-to-head will probably determine who wins the AFC East.

No other team is as hard to prepare for, because the Patriots do so many different things well. They have four receivers who can contribute every week and a quarterback who knows how to spread the ball around. The addition of running back Corey Dillon this year lets them grind it out on the ground and pressure opponents by controlling the clock when they need to.

Perhaps most importantly, the New England defense just doesn’t have any soft spots. They’ll attack the Jets banged-up offensive line with stunts and blitzes to keep Pennington off balance. The last time these two teams met, the Jets’ quarterback was sacked four times and threw five interceptions.

The Patriots haven’t lost at home since December 2002, when Gang Green gave them a 30-17 trouncing. For the Jets to repeat that success, they’ll need to play 60 minutes of football with the kind of intensity they displayed in the second half yesterday. If they come out flat again, they won’t be able to come back against the defending Super Bowl champions as they did against the struggling 49ers.

***

After three straight losing seasons, the Detroit Lions surprised everybody by starting the season 3-1. An infusion of young talent helped jump-start the offense, but a 38-10 loss to the Packers revealed that this team isn’t quite ready to contend.

To begin with, injuries have decimated the Lions offense. WR Charles Rogers will miss the rest of the season with a broken collarbone. RB Kevin Jones has been hampered by a knee injury all year, and rookie receiver Roy Williams spent yesterday on the sidelines with a sprained ankle.

The Lions didn’t win a road game from 2000-2003, a span of 24 games. This year they’re 2-0 on the road, but with all of those injuries on offense and a defense that’s ranked 28th, the Lions aren’t likely to beat the Giants next Sunday at the Meadowlands.