SAN DIEGO -- The No. 19 San Diego State Aztecs didn't take too kindly to seeing star running back Rashaad Penny coming off the field in pain after having his right eye gouged by a Northern Illinois player in the second quarter Saturday night.

"It got us fired up," cornerback Kameron Kelly said after the Aztecs got some big plays early and then held off NIU 34-28 to improve to 5-0 for the first time since 1975. Juwan Washington brought back the opening kickoff 96 yards for a touchdown and freshman Tariq Thompson had two interceptions -- including an 83-yard TD return.

Kelly said there was smack talk from NIU before the game. And then TV cameras picked up Antonio Jones-Davis sticking his hand into Penny's facemask while the star running back was at the bottom of a pile after returning a kickoff.

"If that's their attitude, we've got to have the same attitude, between the whistles, start making them feel it between the whistles," Kelly said.

Penny went into the locker room for eye drops. When he returned to the game, there was a visor installed in his facemask.

"I just think that stuff shouldn't happen," said Penny, the nation's second-leading rusher coming in who was held to 107 yards on 25 carries for his lowest output of the season. "I thought we were all more mature than that. I bounced back. I can't thank my teammates enough. They picked me up when I was down. It was all them. It was a great win."

NIU coach Rod Perry said he talked to Jones-Davis "and he admitted it to me. I'm going to get home and let the emotions die down and see what the next steps are. He's a great kid but it was the emotions of a 22-year-old. But we are going to deal with it, for sure."

While he wasn't pleased to see it happen, SDSU coach Rocky Long said, "A lot of times things like that happen when you're in a pile. They just happened to get it on TV or no one would have known but us because he came to the sideline with his eyes hurting. But since they got it on TV, it's a big deal.

"Stuff like happens all the time," Long said. "I'm not saying it's right, because it's not right. It's not right for any player to be doing that kind of thing. In those piles, you don't know what's going on. It's been a long time since I've been in one, but it used to be nastier than it is now."

Penny caught a 33-yard scoring pass from Christian Chapman in the first quarter. It didn't help the rushing game that guard Antonio Rosales, the only senior on the line, was out with an ankle injury.

SDSU (5-0) is off to its best start since going 8-0 to open the 1975 season. It finished 8-3 that year.

The Aztecs took a 31-14 halftime lead and had to hold on after NIU (2-2) closed to 31-28 in the third quarter. Daniel Santacaterina threw his third TD pass of the night, an 81-yarder to Spencer Tears, on the second play of the quarter, and Marcus Childers scored on a 1-yard run.

John Baron's 21-yard field goal on the second play of the fourth quarter gave SDSU a 34-28 lead.

It took two interceptions in the final minutes to seal it, first by Kameron Kelly at the goal line and then by Thompson with 1:42 left.

Washington, Penny's backup, got the crowd buzzing with the Aztecs' eighth kickoff return for a score since 2015.

The Huskies had two good drives capped by touchdown passes from Santacaterina to Christian Blake, the first for 34 yards and then for 10 yards.

They were sandwiched around a fumble by Andrew Parchment that was recovered by Andrew Aleki. On the next play from scrimmage, Chapman hit Penny coming out of the backfield for a 33-yard score and a 14-7 lead.

With the score tied at 14, Thompson -- who played at San Diego's St. Augustine High -- jumped a route and raced into the end zone, with Santacaterina his closest pursuer.

Chapman threw an 8-yard TD pass to Kahale Warring, and Baron kicked a 38-yard field goal for a 31-14 halftime lead.

Jordan Huff had 148 yards on 25 carries for NIU.

THE TAKEAWAY

NIU: Although they looked dominating on two of their first three possessions, the Huskies, coming off a bye, failed to follow up on their 21-17 upset at Nebraska two weeks ago. The Huskies are winless in six games against the Aztecs, including in consecutive seasons.

SDSU: The Aztecs were playing their first home game as a ranked team since Nov. 11, 1995. Then No. 25, they lost 34-31 to Wyoming and promptly fell out of the rankings. Their No. 19 ranking coming into this game tied their highest spot since 1978. The highest they've ever been was No. 13 in 1975.

"We're starting to have an obsession with winning," Kelly said. "We've got to keep that going. We can't lose. We can't even get this close to losing again."

UP NEXT

NIU begins Mid-American Conference play when it hosts Kent State on Saturday afternoon.

SDSU returns to Mountain West play when it visits UNLV on Saturday night. The Aztecs are the two-time defending conference champions.

---

More AP college football: http://collegefootball.ap.org and https://twitter.com/AP-Top25