ATLANTA — Georgia Tech is used to beating teams with its relentless ground game.

Defense and a long throw?

Now that’s a change.

Two big plays — one provided by the defense, the other on a jump ball of a pass — carried Georgia Tech to a 30-20 victory over Duke on Saturday, ensuring the Yellow Jackets will be eligible for their 14th straight bowl appearance despite a disappointing season.

Mario Butler returned an interception 85 yards for a touchdown, putting Georgia Tech (6-5, 4-4 Atlantic Coast Conference) ahead for good midway through the third quarter.

“It was longest I’ve run since high school,” Butler quipped.

Tevin Washington, filling in at quarterback for injured Joshua Nesbitt, provided some breathing room with a 79-yard scoring pass to Stephen Hill with 71/2 minutes remaining. Georgia Tech completed only one other pass in the game.

With the win, the Yellow Jackets snapped a two-game losing streak and extended their conference record for years finishing at .500 or better in the ACC to 16 in a row. They also avoided the prospect of going into next Saturday’s regular-season finale at rival Georgia still looking for that necessary sixth win to earn a bowl trip.

They’ll take it, even though this season hasn’t lived up to expectations.

“We didn’t accomplish a lot of goals we set,” said coach Paul Johnson, whose team won the ACC a year ago but didn’t come close to defending its title. “We still have a chance to play an extra game. These guys know they’ve got two games left.”

Georgia Tech trailed 13-6 after a sloppy, listless first half and was still down when Duke (3-8, 1-6) drove deep into the home team’s territory on its first possession of the second half. But backup quarterback Brandon Connette, in the game for his running skills, telegraphed his only pass of the day.

Butler stepped in front of the short throw into the flats, cut back the other way around the Duke 40, picked up a late block and tumbled into the end zone.

“When I cut across, my hamstring was about gone,” Butler said. “I was looking around to see if there was anybody I could toss it to. Now I have more respect for running backs and their endurance.”

After the Blue Devils cut it to 23-20 on Sean Renfree’s 37-yard TD pass to Austin Kelly, Washington heaved up a pass on third-and-9 from his own 21. The 6-foot-5 Hill reached over shorter cornerback Ross Cockrell to snatch away the ball, then sprinted down the sideline for just the ninth passing TD of the season for the Yellow Jackets.

“You just hate what happened to Russ Cockrell,” Duke coach David Cutcliffe said. “You spend the whole day isolated, and they throw a jump ball up to a guy that’s bigger.”

Duke had a couple of chances to get within a touchdown, but Will Snyderwine missed field-goal attempts from 34 and 54 yards. He had made 18 in a row after hitting on his first two tries of the game, including a 52-yarder.

Renfree completed 30 of 41 for 334 yards, his fifth game 300-yard game of the season and fourth straight game without an interception. But Connette, who ran for a TD and led the Blue Devils in rushing with 32 yards on four carries, made the crucial mistake when he went to the air.

Anthony Allen led another big day on the ground for Georgia Tech’s option offense, rushing for 165 yards on 34 carries to go over 1,000 yards for the season. The team finished with 320 yards on the ground, but it was two non-running plays that made the difference on this day.

Washington, making his second straight start in place of Nesbitt, coughed up a fumble and was just 2 of 7 passing. The sophomore made up for it by rushing for 94 yards and hitting the big throw to Hill.

The Yellow Jackets defeated Duke for the 15th time in the last 16 meetings, including seven in a row. The Blue Devils will take a two-game skid and another losing season into its finale against North Carolina.

“It’s a pretty tough pill to swallow,” Cutcliffe said. “But I’m really proud of our team for where we’ve come to at this point from where we were in the early part of this season. There is no comparison in the two.”

Georgia Tech led 6-3 on a pair of field goals by Scott Blair before the Blue Devils surged ahead, sparked by a fake punt from midfield. On fourth-and-7, punter Alex King took the snap — and took off, picking up 16 yards before he was shoved out of bounds. Connette finished off the drive with his primary skill, running for a 20-yard touchdown.

After the Yellow Jackets settled for Blair’s third field goal on their opening possession of the second half, closing it to 13-9, Renfree led Duke down the field. On third-and-6, he hooked up with Brandon Braxton on a 36-yard completion. Facing the same situation, he converted again with a 7-yard pass to Conner Vernon down to the Georgia Tech 14.

With Connette back in at quarterback, receiver Donovan Varner was thrown for a 6-yard loss attempting a run. Then, hoping to catch the Yellow Jackets off guard, Connette went to the air.

Big mistake.

Butler made the interception that put Georgia Tech ahead for good.