Cornwall's slim hopes of winning the Minor Counties Western Division title have ended despite them making their highest batting total for 10 years.
They made 414-8 against Wales on day one at Usk, but leaders Oxfordshire got the bonus points they needed at Wiltshire to take them over the line.
Brad Wadlan top-scored for Cornwall on Sunday with 108 in their final three-day game of the season.
It means Cornwall cannot now overtake Oxfordshire regardless of the results.
|Cornwall's 2015 Minor Counties campaign|
|Beat Herefordshire by 108 runs in opening match|
|Crush local rivals Devon by 158 runs at Truro|
|Drew with Wiltshire at Grampound Road|
|Ease to 262 run win over Cheshire|
|Lose by 266 runs against title rivals Oxfordshire|
Cornwall's first innings total was their best since hitting 473 against Herefordshire at Truro in July 2005.
Wales were 65 for 2 at the close of play, with the match continuing on Monday.