SOUTH BEND, Ind. -- Grayson Allen scored 21 points and Jayson Tatum added 19 as No. 21 Duke delivered another big Atlantic Coast Conference road win Monday, beating No. 20 Notre Dame 84-74.

Luke Kennard and Matt Jones had 16 points apiece for the Blue Devils, who have won two straight -- both on the road.

Duke (17-5, 5-4 ACC) had all the answers at sold-out Purcell Pavilion.

"We've gone through some hard things," Duke interim head coach Jeff Capel said. "Hopefully, we're through that stretch and we can start seeing daylight."

It was awfully dark in Durham seven days earlier when Duke lost at home to North Carolina State for the first time since 1995. In the days that followed, the Blue Devils were banished from their locker room after a meeting at the home of coach Mike Krzyzewski, who is recovering from back surgery.

Duke answered with two road wins in front of two sometimes hostile sellout crowds.

"We've gotten better," Capel said.

That might be bad news for the rest of the conference. And the country.

V.J. Beachem had a team-leading 20 points for Notre Dame, which has dropped three in a row. The Fighting Irish (17-6, 6-4) had won five of six from Duke since joining the league in 2013.

After opening with five consecutive conference wins, which set a school record, Notre Dame has lost four of its past five.

"It (stinks), man," said Irish junior captain Bonzie Colson, who scored 17 points. "Tough league. We've just got to stay together. That's what it's about. Gotta continue to believe in us and believe in what we can do. We gotta keep staying together."

Notre Dame's reputation as the best foul-shooting team in the nation coming in (81.5 percent) took a serious hit. The Irish finished 19 of 28 from the stripe, including a crippling 10 of 16 in the second half. Many of those misses arrived when the game was there for the taking.

Instead, the Irish let another one get away.

"I don't know, man," Colson said of the free-throw failures. "It's something we've got to take our time in and knock those in. It's kind of frustrating when you miss those."

Has fatigue become a factor?

"It could be," Colson said. "But we've just got to stay focused and take our time in that part of the game and look them in."

Down by 13, Notre Dame responded with an 8-0 run to cut the deficit to 63-58 with 7:34 remaining in the second half. The burst was highlighted by a three-point play from sophomore Rex Pflueger, and a big wing 3-pointer from Matt Farrell.

Colson added two baskets to bring the Irish within one.

Unable to get any rhythm going on offense, Notre Dame labored through the final 3:41 of the opening half without a point, and the final 8:43 without a basket. That dropped the Irish to a 12-point deficit at halftime, their largest halftime deficit of the season.

It also were the fewest points scored in a half by Notre Dame, which had no answers.

NOTES: Monday's game was attended by 35 NBA scouts from 21 different teams. ... Both teams slid in Monday's Associated Press poll. The Irish went from No. 14 to 20 following an 0-2 week; the Blue Devils went from No. 17 to 21 after going 1-1. ... Hall of Fame coach Mike Krzyzewski missed his seventh straight game following Jan. 6 back surgery. ... The Blue Devils are one of three teams (Arizona, UCLA) with three players averaging at least 15 points per game -- G Luke Kennard (20.4), F Jayson Tatum (15.8) and G Grayson Allen (15.3). ... Monday was Notre Dame's fourth sellout of the season, all in ACC play. ... The Irish slipped to 1-5 against ranked teams with the win over No. 13 Louisville. ... This was Notre Dame's first Big Monday game since a visit to North Carolina to end the 2014 regular season.