NEW YORK -- Mike Krzyzewski didn't want to use inexperience or looking past a below-.500 opponent as an excuse for Duke's 81-77 upset loss to St. John's at Madison Square Garden on Saturday.

The Duke coach didn't mince words in his criticism.

"We didn't play basketball the first 32 minutes worthy of our program," Krzyzewski said. "It was disgusting, really."

Duke dropped to 19-4 on the season after losing to a St. John's team that is winless in Big East play at 0-11.

St. John's outscored the Blue Devils 32-14 in the first 12 minutes of the second half to take an 11-point lead. Duke had a late offensive surge to take a one-point lead with 1:34 left, but Shamorie Ponds (33 points) fired off five straight points, and St. John's held on in the final seconds for a four-point win.

The Red Storm had their way with Duke's defense for most of the game, getting to the rim off the dribble at will. They attempted 32 layups or dunks, leading to 40 points in the paint. Once Marvin Clark got in foul trouble in the second half, coach Chris Mullin went with a smaller lineup that included 6-foot-7 Bashir Ahmed at power forward and 6-3 Bryan Trimble on the wing. The Red Storm, especially Ponds, were able to spread out the Duke defense and attack.

"That was the game plan," Ponds said. "Get the bigs involved in pick-and-rolls."

That's what opponents have tried to do to Duke all season, and it's how Boston College and NC State beat the Blue Devils early in ACC play. The blueprint is out there, and that fit perfectly into what St. John's looks to do in the half court: create mismatches in isolation settings and take advantage.

"It was tough for us to defend them," Krzyzewski said. "They made us look bad -- but we then we made ourselves look bad.

"They scored against our zone defense. They scored against everything."

But here's the thing: Duke's defensive deficiencies aren't a new issue. The Blue Devils have had problems at that end of the floor all season. But this time around, the offense wasn't enough to bail them out. St. John's, despite its poor overall record (11-13), has been a top-50 unit in terms of defensive efficiency for most of the season, but the Blue Devils were significantly below average (for them) on the offensive end. There was a 3:57 stretch in the second half where Duke didn't score a point, and a 7:06 stretch when it made only one field goal.

In the first 14:36 of the second half, Duke made only five shots from the field.

"They didn't respond to anything until the last eight minutes," Krzyzewski said. "That's unacceptable. You have to respond while it's going on."

Grayson Allen made his first field goal with 35 seconds remaining. He's now averaging just 8.5 points in Duke's four losses. With Allen struggling and Marvin Bagley III in foul trouble, the Blue Devils couldn't get anything going in the half court.

Turnovers have been an issue for Duke for most of the season, with the Blue Devils coughing it up on at least 20 percent of their possessions five times in their past nine games and four times in their past six. On Saturday, they turned it over 18 times, leading to 24 St. John's points. Especially in the first half, when Duke was getting open shots from the field and consistent second-chance points, turnovers kept the Red Storm in the game.

"We've been averaging about 16-17 turnovers in the last six games, and we were good enough to overcome that [besides the Virginia game]," Krzyzewski said. "You can't win at a really high level doing that."

In terms of Duke's potential as a title contender, most people have generally overlooked its defensive issues -- because of the Blue Devils' talent and potential on the offensive end. Duke had problems on the defensive end against Indiana, Florida State and Michigan State, but the offense was more than good enough to overcome it. The Blue Devils now rank No. 69 at KenPom in terms of defensive efficiency, yet their No. 2 offense still makes them look efficient as a whole.

When Duke's offense isn't there for 40 minutes, though, suddenly the Blue Devils look a lot more vulnerable. And we've now seen twice in eight days what happens when Duke's offense goes through droughts. It happens to everyone against Virginia, but now it has happened against St. John's. And going back to those earlier losses to Boston College and NC State, not only has the Blue Devils' defense let them down, the offense didn't show up.

Duke has scored 1.15 points per possession or fewer nine times this season -- and it has lost four of those games.

"Young is more susceptible to inconsistency," Krzyzewski said. "And that's what we are. We're inconsistent. In games we've lost, we've been incredibly inconsistent."

Duke still has arguably the highest ceiling of any team in the country because of its talent, but the Blue Devils are not going to be able to win six games in a row against quality competition if they continue to struggle defensively -- not only because it keeps lesser teams in the game, but because it begins to put too much pressure on their offense.

And on Saturday, we saw what happens when the offense isn't there to bail out Duke's defense.