GAINESVILLE, Fla. — Tim Tebow and No. 11 Florida looked like the juggernaut everyone expected this season.

Tebow threw two touchdown passes to Percy Harvin and ran for a score, and the Gators thumped defending national champion LSU 51-21 tonight in The Swamp.

The fourth-ranked Tigers (4-1, 2-1 Southeastern Conference) had won six consecutive games, 19 in a row at night and 23 straight in regulation. Florida (5-1, 3-1) ended all those streaks with a fast start and some huge plays from Tebow, Harvin, Jeff Demps and Brandon Spikes.

The Gators also may have put to rest all those uneasy feelings about an inconsistent offense and a suspect defense. They enjoyed their best game of the season — maybe their best game since beating Ohio State 41-14 in Arizona for the 2006 national title.

LSU, meanwhile, lost for the first time in regulation since falling 23-10 two years ago in Gainesville — taking the worst beating of coach Les Miles' four-year career with the Tigers. They had three turnovers, a near interception that went for a touchdown and a costly face-mask penalty.

LSU trailed 20-0 late in the first half, but scored touchdowns going into the locker room and coming out to make it a game and put all the pressure on Florida.

Tebow hardly flinched, responding with a 67-yard TD drive that included a perfect pass to Louis Murphy down the sideline and a few nifty runs.

The Gators pulled away from there, getting a 42-yard TD run from Demps, a 52-yard interception return for a score from Spikes and a short TD run from Kestahn Moore.

Tebow finished 14-of-21 passing for 210 yards. He also ran 12 times for 22 yards. Harvin had six catches for 112 yards.

Maybe the biggest difference between this game and others this season for Florida was the 2007 Heisman Trophy winner got plenty of help.

Demps ran 10 times for 129 yards. Chris Rainey added 66 yards on the ground. The Gators finished with 265 yards rushing and outgained LSU 475-321.

Jarrett Lee, a freshman making his first SEC road start for LSU, was 23-of-38 passing for 209 yards, with two touchdowns and two interceptions. Charles Scott, who had run for 100 yards in each of his first four games, finished with 35 yards on 12 carries for the Tigers.

After having just about everything that could go wrong go wrong early, LSU caught a break in the final minute before halftime.

Trailing 20-0, Trindon Holliday fielded a kickoff near the sideline and stepped out of bounds at the 13. But officials said by rule, the kick was out of bounds, which gave the Tigers the ball at the 40.

Lee directed a six-play touchdown drive in 44 seconds. He rolled right, and with Spikes bearing down on him, floated a pass to Chris Mitchell in the corner of the end zone.

LSU had 65 yards in its first five possessions, but doubled that with the late TD drive.

The Tigers started the second half in similar fashion, driving 80 yards for a touchdown to cut the lead to 20-14 and make just about all the 90,684 at Florida Field a little nervous.

Not Tebow.

He brought the Gators right back and gave the first matchup since 1990 between the previous two national champions a familiar feel. The home team had won the previous five meetings. Make it six in a row.

The Gators scored on their first three possessions and jumped out to a 17-0 lead. Although they outgained LSU 186 yards to 4 in the first quarter, they got all sorts of help from the Tigers in building a big lead.

Tebow's second pass of the game was a deep ball to Harvin, the kind of play that had been missing much of the season from Florida. It was underthrown, though, and safety Danny McCray nearly knocked it down. But he tipped it right into Harvin's hands. The speedster showed no signs of the ankle injury that caused him to miss practice this week and outran two defenders to the end zone.

The 70-yard pass play was the longest of Tebow's career.

He was just getting started, too.

LSU followed with a three-and-out, thanks partly to Lee's errant pass to Mitchell, and Tebow drove the Gators 77-yards to set up a short field goal.

The Tigers looked even more inept on their second drive and had to punt again. Brandon James, who's already returned two punts for touchdowns this season, nearly broke another one. He got past the first wave of defenders and might have gone all the way had he not cut inside punter Brady Dalfrey.

James ended up with a 40-yard return. LSU looked like it would finally stop Tebow & Co., but Marlon Favorite got flagged for a face mask that turned a third-and-long play into a first down.

Tebow hooked up with Harvin again five plays later, this time from 7 yards out, and Florida was up 17-0.