Bucks suffered their third successive defeat in the Unicorns Counties Trophy when they lost to Oxfordshire by eight wicket in a rain-shortened match at Wormsley on Sunday.
Bucks never recovered after slipping to 43-5 having been put into bat in seamer-friendly conditions. Following a long interruption after a thunderstorm, Bucks eventually reached 152-8 from a reduced 35 overs.
Oxon, whose original Duckworth/Lewis target of 148 from 35 overs was further reduced by bad light to 128 from 31 overs, eased home in reply with eight wickets and 16 balls to spare.
After Chad Keegan had dismissed Shaan Khan with the fourth ball of the game, Bucks lost three quick wickets to the swing bowling of Karl Penhale, a former Bucks Academy player.
The 23-year-old bowled Jack Scriven, had Bucks skipper Michael Payne adjudged caught behind and then trapped Hamza Riazuddin leg before to leave the host county in big trouble.
Robin Pritchard and George Russell then fell to the seam bowling of Ollie Wright to leave Bucks in disarray on 70-6.
The home side partially recovered thanks to a seventh-wicket stand of 59 between Dan Hampton and Matt Rance before a huge thunderstorm halted play immediately after Hampton had departed for 48.
In the shortened game, Bucks reached 152-8, leaving Oxon a D/L target of 148.
They lost Joe White, playing across a straight one from Simon Stanway, in the first over.
But Lloyd Sabin, striking three sixes raced to his half-century in just 52 balls.
He departed soon after a 20-minute break for bad light, but Hugo Darby (51no) ensured Oxon kept their 100 per cent record at the top of the group.
Buckinghamshire face Herefordshire in their next Group 4 match this weekend.