USC Football entered their Week 5 matchup as the No. 6 team in the country. They won their Week 5 matchup by a dominant score of 42-25, but it wasn't enough to move up in the AP Top 25 Poll. But, it wasn't really USC's performance that is why SC didn't move up. Sure, USC's defense gave up 17 points and 218 yards in the first half, but they only gave up eight points and 113 yards all second half.
The offense cooked early and often, not only scoring 42 points but also racking up 485 total yards on the day. So, it really wasn't how USC performed that prevented them from advancing in the rankings.
It's simply that everyone else ahead of them also won. In fact, even the one team ahead of them who dropped (Georgia) was all the way up at No. 1, so SC wasn't going to jump them even with them moving down. Georgia did move down to No. 2, but they are also 5-0 with a Win against an Oregon team who is currently ranked No. 12. They are more proven right now than USC.
USC Football should be happy with their No. 6 ranking.
USC Football is properly ranked, especially considering that the team one spot below them (Oklahoma State) could even have a case to be ahead of them after they are also unbeaten and beat then No. 16 Baylor on the road by multiple scores this week. That's the only team that could have a case ahead of USC, though, so it's not like SC can be argued to be particularly over-ranked.
They're 5-0, and have outscored their opponents 211-98 through five weeks. They haven't played any ranked teams yet, but their job therefore has been to dominate their opponents, and they have done that. The only team that stood a chance against them was Oregon State, but SC still beat them IN Corvallis.
SC's weakest side of the ball is defense, but they're still giving up less than 20 points per game and are tied for top five in the country in sacks (19). They are also tied for first in the nation with 15 turnovers forced, to go along with being first in both interceptions (12) and interceptions returned for touchdowns (three).
If their weakest side of the ball is performing like this, they're clearly a brutal team to try to beat. Clearly, they're a top seven team at WORST right now. SC will stay home this upcoming week to play Washington State, who has had a decent season at 4-1, and almost beat Oregon two weeks ago.