Frankie Sawyer’s tenth goal in seven games proved too little too late for Sevenoaks Town at Belmont on Saturday.
The in-form striker pounced four minutes from time, stabbing home substitute Byron Walker’s knockdown to set up a frantic finale.
Ben Wilson and fellow sub Josh Froggatt both had stoppage-time efforts saved by Dan Eason, but Town had left themselves too much to do.
Two Ricky Freeman goals in the space of as many minutes put the home side in the driving seat by half-time.
Earlier Eason touched Kenny Pogue’s effort for a corner, then blocked Sawyer’s near post effort a minute before the interval - with Pogue, booked for an early challenge on the keeper - unable to make anything of the rebound.
Town stopper Jack Bradshaw then blocked Shaun Welford’s point blank header before Whitstable went in front four minutes later. Sevenoaks lost possession in midfield, home defender John Walker got down the right, and his cross was tucked away by Freeman.
The visitors were caught out again down the left soon afterwards - Walker crossed for Freeman to add another far post finish.
The home striker almost got his hat-trick six minutes later, seeing his free-kick fall inches wide of Bradshaw’s right hand post.
Whitstable went close to adding a third two minutes after the interval, but skipper James Morrish’s cross eluded Welford at the far post.
Sevenoaks had two loud appeals for handball, but struggled to make any impression on the home back four, determined to extend an unbeaten 14-match run in all competitions.
Sevenoaks who went into the game 13 points ahead of their hosts, suffered another blow when latest signing Jack Mahoney limped off four minutes before the interval on his debut with a foot injury.