ATLANTA — Georgia Tech finally got tested.

Give the Yellow Jackets a passing grade.

Georgia Tech (4-0, 1-0 Atlantic Coast Conference) moved up four spots to No. 21 in The Associated Press poll on Sunday after its latest triumph, a gritty 35-28 win over North Carolina that was nothing like the first three games.

The Yellow Jackets romped in those contests, winning by an average margin of 37 points. The Tar Heels made things a lot tougher, rallying from a 14-point deficit to tie it the fourth quarter. Georgia Tech responded with the winning touchdown, showing it can pull out a close game, too.

“We got our first big test,” said quarterback Tevin Washington, whose 5-yard touchdown run won it. “We had to fight through.”

With easier games in the first half of the season, the Yellow Jackets have a chance to build some momentum heading into the tough closing stretch. Already, they are off to their first 4-0 start since 1990 — the year they were voted national champions in the coaches’ poll — and should be favored in their next two games at North Carolina State and back home against Maryland.

“We learned a lot from this game,” said receiver Stephen Hill, who had six catches for 151 yards. “It shows that games are not going to be easy. After blowing out the first three teams by 40 points and over, I’m kind of glad it happened this way. It showed that we can fight. Our backs were against the wall and we came punching back. We know we can do it.”

Georgia Tech will face some much tougher games down the stretch, so it’s important that coach Paul Johnson’s squad keeps building confidence from week to week. Already, they seem to have shaken off last year’s 6-7 record.

“They’re more experienced. They’re a little better at their craft than they were a year ago. They understand a little better,” Johnson said. “I never questioned their toughness. I think we’ve got tough kids. They couldn’t make it through my butt if they weren’t tough.”

They’re certainly running Johnson’s triple-option offense to perfection. North Carolina (3-1, 1-1) focused on taking away the option pitch, so Washington had to hang on to the ball and wound up running 25 times for 74 yards. He also managed to burn the Tar Heels with some deep throws, including a 59-yarder to Hill with no one else around.

Georgia Tech continues to lead the nation in scoring (53.25 points a game) and total yards (630.5), and it could’ve been even more.