No. 19 Southern California will begin its closing four-game stretch of the season in the thick of both the Big Ten Conference championship and College Football Playoff races.The Trojans will face another stout defense in Northwestern on Friday night in Los Angeles.Southern California (6-2, 4-1) will return home for the first time since a 31-13 win over then-No. 15 Michigan on Oct. 11, bookending its Oct. 25 bye with a 34-24 loss at rival Notre Dame and a 21-17 victory at Nebraska last Saturday.The grind-it-out defeat of the Cornhuskers helped land the Trojans at their position in the first playoff rankings of the season.Northwestern (5-3, 3-2) will visit the Los Angeles Memorial Coliseum for the first time since 1969 in the program’s first matchup with Southern California since the 1996 Rose Bowl Game. No Wildcats squad has ever beaten the Trojans, going 0-5 in a series that started in 1952.This season’s Wildcats come in off of a bye week, having last played on Oct. 25 against Nebraska. The Cornhuskers snapped Northwestern’s four-game winning streak in a 28-21 decision in Lincoln, Neb.The 28 points the Wildcats allowed were almost the team’s high for the season, save a 34-14 setback to Oregon on Sept. 13. Northwestern allowed just 42 points combined in wins over UCLA, Louisiana-Monroe, Penn State and a shutout of Purdue between the two losses.The Wildcats are allowing an average of just 16.8 points per game this season, which is the 13th fewest in the nation.The Trojans’ output dipped to 39.8 points per game after the win over Nebraska, still good for eighth-most nationally. Quarterback Jayden Maiava remains ranked in the top 10 of the FBS for average passing yardage with 289.4 per contest.