Sam Darnold (14) will be a key figure to watch for when USC faces Notre Dame in South Bend. Getty

The USC Trojans (6-1) began the season ranked No. 4 in the nation, while the Notre Dame Fighting Irish (5-1) were unranked and looking like a program in its rebuilding stage. But the wide gap between the two storied rivals has closed entering Week 8, with USC heading to Notre Dame Stadium in South Bend, Indiana, on Saturday night at No. 11, while the Irish are not far behind at No. 13.

The Fighting Irish enter the matchup as a 3.5-point favorite — a line that seemed unfathomable before the start of the season. Brian Kelly's squad lost a tight game to Georgia in South Bend on Sept. 10 but has effectively bounced back with four straight victories including a 38-18 road win over Michigan State and last week's 33-10 win over in North Carolina in Chapel Hill.

Running back Josh Adams (129.3 yards per game) has been highly productive for Kelly. The junior could surpass his rushing total from 2016 with a strong performance against USC. Adams rushed for 229 yards against Boston College and 118 yards against North Carolina and has shown breakout speed. But Adams will face his biggest defensive test Saturday since the loss to Georgia, when the Bulldogs held him to just 53 yards on 19 carries.

Defensive coordinator Mike Elko has been credited with containing opposing offenses better than in 2016. Defensive linemen Daelin Hayes, Julian Okwara and Jerry Tillery could put a lot of pressure on the Trojans' offense, while the secondary boasts strong performers like Shaun Crawford and Drue Tranquill to slow down USC's passing game.

The Trojans have played a tough schedule, defeating then-No. 14 Stanford at home, while also managing very close wins over Texas and Utah. But a road loss to then-No.16 Washington State saw USC plummet in the rankings.

While Clay Helton has one of the best quarterbacks in the nation in Sam Darnold, the running game remains crucial for the Trojans. Ronald Jones has scored a touchdown in every game this season, including a 56-yard touchdown reception against Texas.

Defensive coordinator Clancy Pendergast has a star in Cameron Smith and some unheralded stars in the secondary. But USC will try to overcome the absence of standout outside linebacker Porter Gustin. Speedy running back Stephen Carr is also out for USC.

This is the 89th meeting between the two schools. Notre Dame has been on the losing end of the rivalry in recent years. At the Coliseum last year, USC cruised to a 45-27 win and the Trojans have won 11 of the last 15 meetings.

"Last year, Coach Kelly was dealt a hard hand because of the injuries he had (on the roster), especially late in the season," Helton said. "Right now, they're a healthy club."

The matchup should be a high scoring affair with an over/under of 64 points.

Prediction: The Trojans have looked sharp since their narrow defeat to Washington State. Expect Helton to keep things simple and continue the ground attack to win the possession game. Notre Dame should put up a strong fight, but USC has too many weapons and should avoid making crucial mistakes.

Predicted Score: USC over Notre Dame, 35-28

Start Time: 7:30 p.m. ET
TV Channel: NBC

Live Stream: NBC Sports