James Kettleborough's batting kept Northamptonshire afloat as Kent continued to dominate the Second XI Championship match at Beckenham on Wednesday.
The 20-year-old hit an unbeaten 79 as the County closed on 141-4 in their second innings - still trailing by 214 with a day to go.
Resuming on 232-1, the hosts powered on to 506-3 before declaring with Daniel Bell-Drummond undefeated on 212 and Sam Billings 116 not out. Spinners Vicram Sohal and Dan Woods claimed a wicket apiece.
Going in again 355 runs adrfift, Northamptonshire soon lost Stephen Peters for 7, and although Josh Tolley (33) battled hard it was only Kettleborough's efforts that gave the County an outside chance of saving the match on Thursday.