SOUTH BEND, Ind. (AP) -- Navy knew it needed to play nearly perfectly to beat No. 15 Notre Dame.
The Midshipmen didn't, not even close.
Navy (4-1) saw its eight-game winning streak come to an end as three turnovers, three penalties for 41 yards and a potent Irish offense were too much to overcome in a 41-24 loss Saturday.
"We had some penalties, some turnovers, some missed assignments, that normally we're pretty clean on those phases," Navy coach Ken Niumatalolo said. "Against a good team like Notre Dame, that spells disaster. That's what happened to us."
Notre Dame running back C.J. Prosise made Navy pay for its turnovers. He scored one play after linebacker Jaylon Smith recovered a fumble by Chris Swain on the Navy 7 and two plays after Devin Butler recovered a fumble by Dishan Romine at the 26-yard line on the opening kickoff of the second half.
"Huge, huge," Notre Dame coach Brian Kelly said of the turnovers. "Those obviously meant a lot in this game."
Navy had tied the score at 21-21 with 24 seconds left in the first half after 253-pound fullback Quentin Ezell gashed the Irish for touchdown runs of 45 and 22 yards.
"It was a good feeling at the time helping my team catch up when we were behind for a little bit. But obviously it wasn't enough," Ezell said. "We weren't executing like we know we can. To run the option you have to be disciplined and we weren't as disciplined as we were in games past."
Justin Yoon kicked a 52-yard field goal in the closing seconds of the first half and Prosise put the Irish (5-1) ahead by 10 points with a 22-yard run following the second fumble.
Prosise, who was held to 50 yards on 15 carries in a loss a week earlier against Clemson, scored on runs of 7, 22 and 11 yards and finished with 129 yards rushing as the Irish amassed 459 yards total offense.
"It felt great getting back out there and having some big holes again," Prosise said. "They weren't loading the box like last week, and we just had to be able to make some plays on the perimeter, too."
Prosise joins Frank Lonergan in 1902 and Reggie Brooks in 1992 as the only Irish running backs to rush for three touchdowns twice in the same season.
Navy quarterback Keenan Reynolds sat out part of the second quarter and the end of the game after falling awkwardly on his left leg while being tackled.
"It's sore but nothing major is wrong. I just have to rehab it, ice, etc. but I'll be fine," he said.
Reynolds finished with 110 yards rushing on 15 carries but the Irish held him without a rushing touchdown for a second straight season. Keenan remains at 73 career rushing touchdowns, four shy of the NCAA record set by Wisconsin's Montee Ball. His replacement, Tago Smith, threw an interception in the fourth quarter. He guided Navy to two touchdowns in the second quarter.
Reynolds said the turnovers were too much to overcome.
"Obviously, turning the ball over is always a turning point, and giving them some momentum and some good field position. You can't do it at all but especially you can't do it in your own territory. It was inside the red zone both times and that was big for us," he said.
The Midshipmen came into the game averaging 340 yards rushing a game and finished with 318, but couldn't overcome the turnovers. The Irish also held Georgia Tech below its average in a win three weeks ago and are now done with the triple option.
"Thank God," Kelly said. "I think we established something that I wanted to establish and that is a base way of playing the option teams. It's something we can carry with us."