Oakdale moved from outside the top 20 schools to 17th, with Kearsney losing their spot in the elite group.
While the top six schools remain unchanged after all of them were victorious over the weekend, it is below them where all the movement takes place.
With their narrow 23-22 win over Outeniqua, Oakdale move into the rankings with Kearnsey, who didn't play, falling out. Menlopark's 41-29 loss to Garsfontein sees them drop three places from seventh to 10th, which means Glenwood, Paarl Boys' and Paul Roos all climb one spot.
Grey High and Wynberg swap places in the 13th and 14th slots, after Grey beat Wynberg 31-18.
In the bottom five, Outeniqua slip from 16th to 18th, Nelspruit jump from 17th to 16th and Affies downgrades from 18th to 20th.
FNB Top 20 schools rankings
1. Grey College
3. HTS Middelburg
4. EG Jansen
8. Paarl Boys'
9. Paul Roos
12. Paarl Gym
13. Grey High