The pint-sized striker struck after only eight minutes to launch the Seagulls to their fourth home victory out of five.
Knight had also been the hero of Brighton's 1-0 home win against Chesterfield four days earlier on his 21st birthday.
He has a special incentive against Wednesday after an unhappy loan spell with the Yorkshiremen from Chelsea last season.
In the build up to the match Knight accused Turner of making his life a misery and causing him to consider quitting football.
He pointed towards Turner in the dugout from the opposite side of the pitch after firing Brighton's early opener.
A Kerry Mayo pass released Knight through the inside right channel. He evaded the challenge of Wednesday skipper Dean Smith to beat Kevin Pressman with a powerful right foot drive.
Brighton could have been out of sight by half time. Charlie Oatway (twice), Darius Henderson and Gary Hart all went close, then Hart smashed a shot against the crossbar in first-half stoppage time.
The pattern of Brighton domination continued after the break as Knight nodded wastefully wide from Oatway's quickly taken free-kick and Henderson looped a header onto the roof of the net.
The injured Knight was given a standing ovation as he was helped off on 73 minutes.
His young replacement Chris McPhee wrapped up the points ten minutes later with his first League goal, a low drive after Guy Butters had crashed a shot against the underside of the bar.
Turner's team were a big disappointment. Out-played for long periods they only tested Michel Kuiper's in the Brighton goal once.
The big Dutchman recalled from a loan spell from Hull because of an injury to Ben Roberts, blocked Adam Proudlock from close range midway through the first half.