San Francisco 49er Coach Bill Walsh figured this was the night his team would make it big. Monday Night Football, national TV, the Big Apple, the works. "You're not really a class team," he said, "unless you win in New York City. Boxers, entertainers, actors, actresses -- they've all done it here."

Now, his team has, too, although, as a drama, his road show might be a hard sell.

If anyone doubted that the undefeated 49ers were for real, 7 minutes 33 seconds of Monday Night Football certainly convinced them. They scored 21 points in that time in the first quarter tonight en route to a 31-10 victory over the New York Giants in front of 76,112 at Giants Stadium.

"I hope they were watching," fullback Roger Craig said of all the viewers who were potential channel-switchers as the 49ers, now 6-0 and off to their best start since 1948, jumped to a 28-3 halftime lead.

"We really wanted to look good tonight, and we did."

The 49ers, led by quarterback Joe Montana's 15-for-24 passing for 207 yards and three touchdowns, took advantage of a blitzing Giant defense with swing passes to the backs to send the Giants to a 3-3 record, one game behind the Redskins and Dallas Cowboys in the NFC East.

The Giants scored their only touchdown of the night with 1:17 remaining in the game on Butch Woolfolk's one-yard run, the first touchdown scored against the 49ers in 12 periods. The few hundred fans remaining at the Meadowlands Complex cheered derisively.

"When you don't give up a touchdown in 12 quarters," Montana said in the locker room, "it's almost impossible for you not to win."

If the Giants, who began the season 2-0 before losing to the Redskins last month, could not slow the 49ers' juggernaut, it's unlikely anyone will for the next month. San Francisco's next five games come against opponents with a combined eight victories.

This game proved a couple things about the 49ers, who, with the Dolphins, are the only unbeaten teams in the NFL. Walsh was pleased that the stars of this game -- Craig (33 yards rushing, seven receptions for 95 yards), Wendell Tyler (101 yards on 14 carries), and Renaldo Nehemiah (a 59-yard touchdown reception) -- were different from the stars of previous games.

"We just feel we have good dimension to this team," he said.

The 49ers looked extremely quick on the artificial surface, cutting back against the grain to break tackles against a blitzing, aggressive Giant defense.

"This surface is made for the runner," said Walsh, who was happy to go to the run to protect his lead and Montana, who has returned from missing a game with bruised ribs.

And it showed how adaptable the 49ers are, going to swing passes to the backs when the blitz came on strong inside.

"That was our game plan," Walsh said. "When they were blitzing, we went to the swing pass to get Craig on single coverage outside."

Montana's first touchdown pass came with less than three minutes gone in the game, a 59-yard deep turnup pattern to Nehemiah, the former University of Maryland world-class hurdler and Superstars winner. Nehemiah worked his way behind cornerback Mark Haynes down the right sideline for his first touchdown of the season. Ray Wersching's extra point gave the 49ers a 7-0 lead.

Four minutes later, it was touchdown No. 2, a one-yard pass from Montana to rookie tight end John Frank. It came at the end of a 75-yard drive that took only 1:53, thanks largely to Tyler's 25-yard run and two 21-yard passes from Montana to fullback Craig. The second Craig reception took the ball to the one, setting up Frank's first NFL reception.

The Giants' next possession ended in Dave Jennings' 39-yard punt to Dana McLemore at the New York 21. Moments later, McLemore ended up in the end zone after breaking three open-field tackles on a 79-yard return for the third San Francisco touchdown.

The Giants finally got things going on their next possession, an 82-yard drive that ended disappointingly in a 20-yard Ali Haji-Sheikh field goal, cutting the margin to 21-3.

After moving with relative ease to the San Francisco three-yard line with a first down, the Giants went through three plays of utter futility. First, tight end Zeke Mowatt fell down as quarterback Phil Simms rolled to his right, looking only for Mowatt. Simms threw the ball anyway for an incompletion.

On second down, a meaningless fake dive into the line drew no attention as Simms again fired incomplete. Finally, on third down, Simms' pass to Mowatt in the corner of the end zone hit free safety Dwight Hicks square in the back and bounced to the artificial turf, forcing the field goal.

The 49ers added their final touchdown of the half on Montana's eight-yard swing pass to Craig with 9:04 remaining in the second quarter. Taking over on their nine, the 49ers relied on two passes to Craig coming out of the backfield and a 10-yard pass to Dwight Clark on third and eight at the Giants' 21 to set up the final pass to Craig for the 28-3 lead.

The 49ers' only points of the second half came on Wersching's 37-yard field goal at 9:14 of the third period. San Francisco's 32-yard drive for the field goal was set up by linebacker Jim Fahnhorst's interception of a Simms pass at the San Francisco 48.