Chinnor produced a battling display to start their National League 1 campaign with a 17-15 victory at Blackheath.
Second-half tries from Tom Fidler and Ofisa Treviranus proved enough as the Thame-based side dug deep to see off their spirited hosts.
Chinnor opened up a 3-0 lead on five minutes, thanks to Laurence May’s penalty.
Blackheath’s Danny Herriott was then sin-binned, but the visitors were unable to make the most of their man advantage.
It took the home side 28 minutes to get out of their own half and they punished Chinnor for not adding to their tally.
Joe Dancer knocked on from a lineout and Jack Daly darted over, Mark Crooke converting, to put Blackheath 7-3 ahead.
Chinnor started the second half strongly and scored two tries in the space of seven minutes through Fidler and Treviranus, May converting both.
But Blackheath refused to lie down as Alex Pickersgill’s unconverted try reduced the arrears, before Cooke’s penalty cut the visitors’ lead to two points with nine minutes to go.
However, Chinnor responded well to see the game out and earn victory.