PITTSBURGH — Grant's 3-pointer bounced on the rim twice and in to give Notre Dame a 29-28 lead, and the Irish went up by three when Cooley tipped in a rebound of a miss by Grant less than a minute later.
Baskets by Cameron Wright and James Robinson gave Pitt a 32-31 lead with 12 minutes remaining.
Robinson missed a 3 nearly a minute later, and Atkins' layup on the ensuing possession put Notre back ahead — and started a 12-2 run that put the Irish ahead 43-34 with 4:48 to go — and they never trailed again.
Notre Dame shot 60.7 percent (17 for 28) after missing 18 of its first 19 shots and limited Pitt to 30-percent shooting (9 for 30) over the final 27 minutes of the game. The Irish improved to 4-1 against ranked teams.
With a game-high nine rebounds, Cooley narrowly missed out on his seventh straight double-double. He had three of Notre Dame's 13 offensive rebounds, and the Irish held a 40-25 advantage on the boards overall.
Pitt was without freshman forward Durand Johnson, who had a stomach virus.