Duke is going the ironman route early in the season.

Playing with a rotation of mostly six players, the Blue Devils withstood a challenge from Penn State to win 78-68 on Saturday in the Basketball Hall of Fame Tip-Off semifinals at Mohegan Sun Arena at Uncasville, Conn.

"We obviously had an injury adversity coming into the game and then we had more in the game," Duke coach Mike Krzyzewski said. "It was a real character game for our kids and a real good game."

Forward Amile Jefferson's 16 points and 16 rebounds propelled Duke, which bounced back from Tuesday night's last-second two-point loss to Kansas.

Reserve guard Frank Jackson added 17 points for the Blue Devils (3-1). Guards Matt Jones, who dealt with foul trouble, and Luke Kennard scored 15 points apiece for Duke. Grayson Allen chipped in 12 points despite playing on a sore ankle.

Duke's recent injury problems, which include three freshmen who have yet to play this season, were compounded when sophomore post player Chase Jeter was helped to the locker room after going down because of an ankle injury in the first half and did not return.

Plus, Allen left briefly to have an ailing ankle re-taped.

"It's a very difficult time for us," Krzyzewski said. "A very unusual time. ... We've got to get as healthy as we can for (Sunday's game)."

Duke takes on the Cincinnati-Rhode Island winner in Sunday's tournament title game, while Penn State (2-2) meets the loser. The Blue Devils will try for their 19th in-season tournament title under Krzyzewski.

Freshman Tony Carr scored 20 points and Shep Garner finished with 15 for Penn State. Payton Banks and Lamar Stephens had 13 and 11 points, respectively.

"There's so much more basketball to go," Penn State coach Patrick Chambers said. "That's what's so exciting for me."

Duke held a 47-30 lead less than three minutes into the second half, but Penn State trimmed that to 60-51 by midway through the second half.

The Nittany Lions were within 72-64 on guard Garner's 3-pointer with 2:36 to play and there was a chance to trim the deficit again before Garner committed a turnover and Carr missed consecutive shots.

"We handled their press," Krzyzewski said. "They tried to wear us out."

Jackson racked up 11 points in the first half, helping Duke to a 36-24 halftime lead. Kennard shot only 3-of-11 from the field before the break as he accounted for half of the shots by Duke's starters.

Penn State failed to capitalize on some of Duke's early lineup adjustments, making only five of its first 21 shots from the field and shooting 27.3 percent (9-for-33) in the first half.

"Our focus is on Penn State and making Penn State better," Chambers said. "Whoever we're playing Sunday, trying to get better that day. ... We need to get there hopefully by Big Ten season."

Duke opponents made only 14.8 percent on 3-pointers through the first three games and Penn State was only slightly better at 27.3 percent (6-for-22).

"You've got to make some 3s against Duke if you want to stay with them," Chambers said.

NOTES: Duke continued to play without injured freshmen Marques Bolden, Harry Giles and Jayson Tatum, all who have yet to make their college debuts. ... Duke leads the series with Penn State by 9-1, although the most-recent meeting had come in December 1970. ... Penn State hadn't played a No. 1 team since 2011. The Nittany Lions dropped to 0-14 all-time against top-ranked teams. ... This was part of six games in two weeks for Penn State, which will tie a program record with eight November games. ... Penn State also played in the 2011 Basketball Hall of Fame Tip-Off, losing to eventual national champion Kentucky. ... Duke G Grayson Allen is three points shy of becoming the 65th player in school history to reach the 1,000-point mark.