The Razorbacks (22-2) were No. 1 for the third straight week and eighth overall this season by a comfortable margin, getting 59 first-place votes and 1,619 points from the national media panel.
Duke (21-3), which had one No. 1 vote, was second with 1,513 points, well ahead of the Wolverines (20-4), who had 1,449 points, including three first-place votes.
Connecticut (24-3), which won the Big East title, and North Carolina (23-5), which each had one first-place vote, switched places from last week and round out the top five.
Missouri, the Big Eight champion, was again sixth, followed by Kentucky, Arizona, Purdue and Louisville, the Metro Conference champs.
It's the first time Penn (21-2) has been ranked since the final poll of the 1978-79 season, the year the Quakers last went to the Final Four.