Frankie Sawyer’s 96th minute penalty ensured Sevenoaks Town ended a run of three successive Bostik League South East defeats at Winch’s Field on Saturday.
Sawyer stepped up to beat former Oaks keeper Simon Overland with the penultimate kick of the game - the second spot-kick in the match - and complete the late come from behind victory.
Bay were left fuming by the decision and Overland was booked at the final whistle for dissent, after referee Alex Emery had pointed to the spot when Alec Fiddes tumbled in the box.
Oaks trailed 1-0 with six minutes, substitute Kenny Pogue firing them level, before Sawyer converted the perfect penalty.
The official contrived to upset both teams.
Oaks were convinced there was a foul in the build-up to Bay’s 70th minute opener by skipper Bradley Schafer.
They also complained when the hosts were awarded a first half penalty, when new left back Ryan Makhosini Khanye handled in the area.
Home debutant striker Andrew Dalhouse was handed the opportunity from 12 yards, but keeper Ben Bridle-Card dived to his right to save, one of three important stops in the closing stages of the first half which kept Oaks level at half-time.
Dalhouse missed out on making amends soon after the break, failing to convert Schafer’s cross, when unmarked, before Oaks went close three times.
Sawyer fired over, and Fiddis went close twice, ahead of Bay breaking the deadlock with 20 minutes left.
They broke quickly as Mr Emery let play continue despite a clear foul in the middle of the park, Danny Leonard eventually crossing for Schafer to score with a low left foot finish inside the far post.
Pogue replaced Luke Coleman after 64 minutes and created two openings, before getting on the end of Khanye’s cross to make it 1-1, the ball going in off a defender - his first goal for a month.
Skipper Tom Ripley headed off the line at the other end, then Dalhouse slid another effort wide of the post, before the controversial climax.
Oaks pressed for the winner, Bay conceding several free-kicks, before Fiddis won the penalty, Sawyer making no mistake for his 13th goal of the season.
Oaks have a poor recent record of converting penalties, and assistant manager John Wilfort was unable to watch before celebrating with the rest of the Oaks bench.
Micky Collins included another new signing, Dan Parkinson from Sittingbourne.
A 55th minute substitute for Oliver Bennett, he picked up a booking with his first challenge - one of four Oaks cautions.