Trying to snap a three-game losing skid, the 49ers flew to Giants Stadium for a Week 7 duel with the New York Giants.  In the first quarter, the Niners trailed early as Giants RB Brandon Jacobs got a 26-yard TD run.  San Francisco would respond with kicker Joe Nedney getting a 40-yard field goal.  In the second quarter, New York answered with Jacobs getting a 2-yard TD run.  The 49ers responded with QB J.T. O'Sullivan completing a 30-yard TD pass to rookie WR Josh Morgan.  The Giants ended the half with kicker John Carney nailing a 21-yard field goal. In the third quarter, New York increased its lead with QB Eli Manning completing a 6-yard TD pass to WR Plaxico Burress.  The Niners struck back as CB Nate Clements returned a block field goal 74 yards for a touchdown.  However, in the fourth quarter, the Giants pulled away as Carney got a 48-yard field goal, while DE Justin Tuck forced O'Sullivan into a fumble, causing the ball to roll into San Francisco's endzone, and Morgan kicking it out of the back of the endzone, giving New York a safety. On Monday, October 20, the day after the game, the 49ers fired coach Mike Nolan and replaced him with Mike Singletary.. How many yards was the longest touchdown in the first half?