(AP) — Ohio State faces an unlikely challenger to its supremacy in the Big Ten.

Purdue, unranked in the preseason, has blitzed through its first five opponents. The Boilermakers see a win over the fourth-ranked Buckeyes on Saturday night as a major step toward their goals of winning the Big Ten title and earning national recognition.

"It's time to go out there and prove we can play with the best teams out there," Purdue defensive end Cliff Avril said. "It can put Purdue on the map for this season."

Defending Big Ten champ Ohio State (5-0, 2-0) again is chasing a national championship after finishing as runner-up to Florida last season. No. 23 Purdue was ranked for the first time in nearly two years, but hasn't played a Top 25 team.

The Boilermakers could make a big jump in the polls by ending Ohio State's 23-game regular-season winning streak. While the prime-time setting might be new to Purdue, Ohio State is comfortable with it.

"I think our guys enjoy the fact that they're going to be on Saturday night and a good bit of the world is going to watch them," Ohio State coach Jim Tressel said. "I think they're excited about that."

Purdue (5-0, 1-0) has been competitive with Ohio State in recent years. The Buckeyes won 10-6 in West Lafayette in 2002 on their way to a national title. They won 16-13 in overtime the next year in Columbus, then Purdue won 24-17 at home in 2004, the most recent meeting.

"Shoot, they've been battles," Tressel said.

Purdue ranks eighth nationally with 45 points per game and is 10th in total offense.

"It's a very explosive offense," Ohio State linebacker Marcus Freeman said. "It's going to be a very tough task making sure that you take care of each playmaker."

Ohio State ranks third in the nation in scoring defense and second in total defense. Its defense has been scored upon just five times this season, and the Buckeyes have only returned 11 kickoffs.

"That tells you something about their defense," Purdue coach Joe Tiller said. "Matter of fact, that should tell you everything you need to know about their defense."

Purdue's offense has been successful for 11 years under Tiller, but statistically, this has been his best unit.

Curtis Painter set the league record for passing yards in a season last year, and he's ahead of that pace now. He's averaging 308 yards passing and has 18 touchdown passes and three interceptions.

Wide receiver Dorien Bryant is among the nation's leaders with 40 catches, 450 yards and four touchdowns. He's especially dangerous in the return game, where he ranks seventh nationally in kickoff return average. Tressel compared Bryant to former Buckeyes receiver Ted Ginn Jr.

"He's got electricity about him," Tressel said. "He's going to be a fun one to watch. I just hope he's not too much fun."

Buckeyes star cornerback Malcolm Jenkins will likely spend the day chasing around Bryant.

Tiller said Ohio State's defense has no weaknesses. Linebacker James Laurinaitis leads the way with 43 tackles.

"He's a very good football player, very physical guy," Tiller said. "He's a much better football player this year, and he was a pretty good player last year. I think he does all the right things."

Purdue has struggled defensively in the second half of its past three games. In the first halves of wins over Central Michigan, Minnesota and Notre Dame, Purdue outscored its opponents 78-3. In the second halves of those games, the Boilermakers were outscored 69-45. They've also been vulnerable to the run.

Ohio State's Chris Wells has rushed for 540 yards and five touchdowns this season and first-year starter Todd Boeckman leads the Big Ten in passing efficiency. He has thrown 12 touchdown passes and three interceptions.

"He's a talented guy where, when you lose Troy Smith, you knew you were losing a talent, but you didn't feel that bad about it because you knew what was in the wings," Tiller said. "He's a very capable guy."

Brian Robiskie leads the Buckeyes with 25 catches for 530 yards and six touchdowns. Slowing him will be a key if Purdue's impressive start will mean anything by Sunday morning.

"One of our goals is to win the Big Ten," Painter said. "Beating a team like Ohio State would put us in position to do that. You have to beat the top teams to be the top team."