Two tries from captain Dan Spencer helped Bicester beat visitors Hungerford 29-19 to go second in the BB&O Premier Division.
Bicester led 29-0 midway through the second half, but did enough to leapfrog their opponents into the second promotion place.
The hosts’ pressure finally told on 21 minutes when No 8 Spencer stormed over for a try, which centre Steve Miller converted.
Miller and fly half Mike Harris combined to send flanker Matt Dye in for try No 2.
Prop Dave Behan was held up, but Bicester were not to be denied a third try when debutant hooker Philip Small dashed over before half-time.
Spencer scored his second two after the break, which Miller converted for 24-0.
Wing Dave Aslett bagged try No 5 to give Bicester an unassailable lead.
Hungerford took advantage of Miller being sin-binned to score through full back Dominic Taylor.
Fly half Bradley Clough converted his own try to make it 29-12.
And he did the same to wing Lance Peplar’s last-gasp try.
Faringdon fell to a 53-10 defeat at high-flying Risborough in the BB&O Championship.
Risborough scored nine tries, while Adam Viner went over for Faringdon’s consolation, with Darren Clark converting having kicked an early penalty.