Answer based on context:

 The Giants recorded their fifth straight victory with a convincing 33-15 win over the San Francisco 49ers at Giants Stadium. Things started off well as the Giants drove right down the field on their opening possession. The balanced, well-executed seven-minute drive was capped off by a 4-yard touchdown pass from Eli Manning to Amani Toomer. The extra point was missed by Lawrence Tynes. On their next possession, the Giants were driving for more, but a tipped ball resulted in an interception inside the red zone. The 49ers responded with a nice drive of their own, aided by a personal foul on linebacker Antonio Pierce and several third down conversions.  San Francisco cashed in with a touchdown from Trent Dilfer to Arnaz Battle. Following a Frank Gore fumble, the Giants took control. The running game, which accounted for 140 total yards helped the Giants move back in front. Brandon Jacobs scored on a five-yard run for a 13-7 lead. After an interception by Sam Madison, the Giants added a 30-yard field goal by Tynes. Tynes made it 19-7 at the half with another field goal, this time from 39 yards, inside the final minute. The Giants defense dominated in the second half, notching six sacks and four total turnovers. Osi Umenyiora put the game away with a sack, forced fumble, and 75-yard touchdown return up the field for a 26-7 lead. The Niners got two points back on a blocked punt out of the end zone but Antonio Pierce redeemed himself for two earlier personal fouls by intercepting Trent Dilfer and returning the ball inside the 10. After a flag on the 49ers, Manning threw his second touchdown, this time to Jeremy Shockey for a 33-9 lead. The 49ers scored late to provide the final points in the 33-15 win. On the day, Brandon Jacobs rushed for 107 yards, Manning completed 18 of 31 passes for nearly 150 yards with two touchdowns and an interception, and the defense notched six sacks: 2.5 for Michael Strahan, 1.5 for Justin Tuck, 1 for Aaron Ross and 1 for Umenyiora. Pierce and Madison provided the two Giants' interceptions. For the fourth consecutive year under Tom Coughlin, the Giants were 5-2 after seven games.

How many points did the Giants win by?
18