Fareham had no answer to high-flying Bemerton in a 3-0 loss at Cams Alders.
Bemerton took a 14th-minute lead when Sanger cut inside and slotted home at the near post.
Fareham were then left to thank keeper Adam Redman for saving at the feet of Sanger after the Bemerton man was put clean through.
The hosts nearly grabbed a leveller just after the half-hour mark as Graham Lindsey got on the end of a Danny Thompson corner, only for his effort to be cleared off the line.
That proved crucial as Bemerton doubled their lead when Louis Martin brought down one of their players in the box and Roberts netted the resultant penalty.
Bemerton dominated after the break and wrapped up the points on 55 minutes when they broke away after a Fareham corner, which eventually saw Bowman slot past Redman.