Georgia Tech's defense had arguably its best performance of the year in the 31-17 upset of No. 5 Clemson on Saturday at Bobby Dodd Stadium.

Jemea Thomas was a big reason why.

The defensive back forced a fumble, had two pass break-ups and two interceptions, including one in the end zone in the fourth quarter.

"Jemea Thomas loves to play football," coach Paul Johnson said. "That's why I've said we've got to get him on the field. He makes plays."

Thomas' interception in the end zone, with Tech leading 31-17, was the turning point in the game.

From watching film, Thomas said he knew the Tigers like to run a fade with Clemson wide receiver Sammy Watkins when they are in the red zone. However, Watkins cut back up the field, appearing to run a curl route. Quarterback Tajh Boyd threw the fade, and Thomas easily made the interception.

"That's the difference in the game," Clemson coach Dabo Swinney said. "If we get that, it's a one-score game with about 10 minutes to go, and we were right back where we wanted to be."

After Tech returned the ball to Clemson with 1:29 remaining, Thomas followed that with another interception on the Tigers' next possession.

The defense had played fairly well during the two-game losing streak preceding the upset, particularly in the loss to Miami, but it wasn't making the type of plays that it made against Clemson. The Yellow Jackets held the Tigers to 399 yards, almost 100 yards less than they were averaging. The 17 points were 23 less than their season average. The Jackets also had two sacks and held the Tigers to 5-of-13 on third down.

"We knew we had a bunch of doubters and whatnot because of the last two games, we just pulled together," Thomas said.

Tech's defense jumped on the Tigers early, with Louis Young forcing a fumble that Rod Sweeting recovered on the 9-yard line in the first quarter.

Tech punched in the touchdown to take a 7-3 lead.

"It was a momentum changer," Young said of the play.

The defense continued to befuddle the Tigers until halftime, holding them to a season-low three points in a half. Clemson also had just 132 yards.

Clemson scored on its opening possession of the second half, with Boyd finding Watkins on a 48-yard crossing pattern. The score cut the Jackets' lead to 24-10 and took less than two minutes and just four plays.

The Tigers were marching again until Thomas stripped Clemson running back Mike Bellamy of the ball. Julian Burnett recovered on Tech's 39-yard line.

The Jackets weren't able to capitalize, with Washington fumbling on the 3-yard line. The Tigers went 97 yards, capped by a 1-yard scoring plunge, to cut the Jackets' lead to 31-17 with 14:47 remaining in the game.

But they couldn't get any closer because of Thomas' two interceptions.

"Jemea Thomas made some huge plays," Johnson said.