Turner's 26 points tied the team's season-high point totals. Lou Williams and Jodie Meeks both have scored 26 this season.
Turner dominated the ball and, in turn, the Sixers dominated the Celtics (20-18), ending their five-game winning streak and dropping them two games behind the Sixers in the Atlantic Division race. For the Sixers, the win was just their third in their last 11 games.
Turner, who also grabbed nine rebounds, was one of six Sixers to finish in double figures.
Playing without Thaddeus Young (upper respiratory tract infection), the Sixers got a double-double from Nik Vucevic (14 points, 12 rebounds).
Elton Brand finished with 18 points and nine rebounds. Andre Iguodala had 10 points, eight assists, and seven rebounds, and Williams and Jrue Holiday finished with 15 and 10 points, respectively.
Paul Pierce and Brandon Bass led the Celtics with 16 and 12 points, respectively.
Turner's best moment of the night came with 6 minutes, 33 seconds left in the third quarter, when, with the shot clock winding down, Turner broke down Pierce and hit an off-balance layup. Fouled on the play, Turner converted the free throw to put the Sixers up 69-43.
Shortly thereafter the Sixers extended their lead to 73-45 when Brand took in a pass from Iguodala and finished it off with a dunk that forced the Celtics to call a timeout
Turner surpassed his previous career high of 23 points, which he scored Dec. 29, 2010, against Phoenix, before he came out of the game with just over one minute left in the third quarter with the Sixers leading by 29.
Just as they had done Monday in Milwaukee, the Sixers began the game by scoring 33 points (on 16-for-26 shooting) in the first quarter.
The best news for the Sixers was the hot start for Turner. After he went 1 for 12 from the field for two points against the Bucks, Turner had 10 by the end of the first quarter, which concluded with the Sixers leading by 16.
Turner continued to play well in the first half, and so did his teammates.
They opened the second quarter on a 14-4 run, capped by back-to-back buckets by Holiday and Turner. The latter came with 4 minutes, 1 second left in the half and gave the Sixers their largest lead to that point, 49-21.
Turner, who had scored just 20 points combined in his last five games, had 16 by halftime. He was not, however, the only Sixer to reach double figures by halftime. Brand had 12.
Meanwhile, the Celtics looked early on very much like an aging team that had just played a pair of back-to-back overtime games.
Contact staff writer John N. Mitchell at email@example.com. Follow him on Twitter @JmitchInquirer