SOUTH BEND, Indiana — Playing six of their first eight games away from home might have been a bit much, even for coach Tom Izzo's road warriors.
Grant had a career-high 27 points and six assists, and Jackson added a career-best 22 points in the first meeting between the schools in 35 years.
"Nobody in our league has played even close to six road games," Izzo said, adding: "The coach is an idiot, and I've said it for many years."
Michigan State (5-3) begins a seven-game home stretch on Saturday.
Izzo thought his Spartans showed signs of wear down the stretch — particularly leading scorer Travis Trice, who has been fighting an illness the past two days. Trice was averaging 16.4 points per game coming in but finished with only seven on 3-of-13 shooting against the Irish.
"I did not think he looked like himself at all," Izzo said. "I didn't see the burningness that you should see out of a senior, and that's what I told him in the locker room. I'm hoping it was because he wasn't feeling well."
Jackson's three-point play 2:19 into overtime put the Fighting Irish (7-1) ahead by five. His free throw with 5 seconds left ended up being the winning margin after Denzel Valentine's 3-pointer in the final second.
Jackson scored six of Notre Dame's 10 points in overtime. Grant had a three-point play and a 3-pointer down the stretch to nearly win it in regulation for the Irish.
"I love my guards," Notre Dame coach Mike Brey said. "I think I have the best backcourt in the country. Not a lot of people talk about them, but if you watched us tonight, it would be hard to argue against it."
Valentine finished with 22 points and Branden Dawson had 16 points and a career-high 18 rebounds for Michigan State.
After Valentine dribbled the ball off his foot to give it back to Notre Dame with 2.3 seconds left in regulation, Grant had a shot to win it on a drive to the hoop, but Valentine stripped the ball at the buzzer to send the game to overtime.
"We did enough good things to win, but we did enough bad things to lose," Izzo said.
Valentine's 3-pointer with just more than two minutes to play tied it 64-all and stopped a 7-0 Irish run. Grant followed with a 3 on the next trip down the floor to get the lead back for Notre Dame, but Valentine answered with another 3 with 47 seconds left to tie it again at 67.
Jackson blocked Matt Costello's dunk attempt and then scored on a drive on the other end, and Grant grabbed a steal and converted a three-point play to give the Irish a 64-61 lead with 4:06 to go.
"He's so clutch," Jackson said of his backcourt mate, Grant. "Sometimes I look at some of the moves he's doing and I'm like, 'I need to work on that.' He makes so many plays."
Consecutive 3-pointers by Grant and Steve Vasturia sparked a 10-0 run late in the first half to give the Irish a seven-point lead. Bryn Forbes hit a fallaway 3 with a second on the shot clock to end that spurt and scored the Spartans' final seven points of the half to cut Notre Dame's lead to 37-35 at the break.
Michigan State: After opening the season by playing six of their first eight games away from home, the Spartans play their next seven in East Lansing.
Notre Dame: It was Notre Dame's first game of the season against a Top 25 team. The Irish went 1-5 against ranked opponents last season.
ON THE BOARDS
Michigan State outrebounded the Irish 43-26, a deficit Brey wasn't sure his team would be able to overcome.
"I knew they'd be able to play volleyball on us. I didn't know it was going to be that bad," Brey said. "At least it didn't beat us."
MISSING IN ACTION
The Irish played without V.J. Beachem, typically the first player off the bench, due to a right foot injury. Beachem, expected to miss a month, is averaging 8.4 points and shooting a team-best 55.6 percent (15 of 27) from 3-point range.
Michigan State hosts Arkansas-Pine Bluff on Saturday.
Notre Dame hosts Fairleigh Dickinson on Saturday.