Turner scored 25 points, Jrue Holiday added 21 and the Sixers held off several fourth-quarter rallies during a 106-100 victory over the Celtics on Friday night.
"I just kept telling our guys ... just try to keep it in perspective when they went on those runs so it doesn't seem like the house is falling down on top of us," Philadelphia coach Doug Collins said.
The 76ers led 57-45 at halftime and 83-74 after three quarters. The Celtics pulled within four on two occasions in the final period, 83-79 and 102-98, but couldn't get any closer and fell to 2-3, with their only victories coming over winless Washington. The 76ers won their second game in three nights to improve to 3-2.
The recurring problem for the Celtics was their transition defense. When their opponent rebounds a missed shot, they're not getting back in time.
The 76ers scored 26 fast-break points.
"I thought we hung in the game, kind of fought back," Boston coach Doc Rivers said, "but every time we needed a stop tonight, we didn't get it."
The Celtics had particular trouble stopping Turner and Holiday, who are handling the ball more after the offseason departures of Andre Iguodala to the Denver Nuggets and Lou Williams to the Atlanta Hawks.
"Now it's just me and Evan" as the key ballhandlers, Holiday said. "Coach kind of puts the ball in my and Evan's hands and expects us to make plays."
Turner also had 11 rebounds and Holiday had 14 assists. Dorell Wright and Thaddeus Young scored 15 points apiece.
Paul Pierce scored 24 for Boston, and Kevin Garnett finished with 19. Rajon Rondo had 14 points and assisted on 20 of the Celtics' 37 baskets.
Boston's last lead was 10-9 on a 20-footer by Courtney Lee midway through the first quarter. Holiday then had a dunk put Philadelphia ahead to stay.
"If we can do a better job of getting back on defense, limit the easy opportunities, we give ourselves a better chance," Pierce said. "Guys on the perimeter have to get back."
Despite their slow start this season after losing in the seventh game of the Eastern Conference finals last season, the Celtics know it takes time for a team with many new players to jell.
"I'm very patient," Pierce said. "I understand it's a process. We're only five games in. We're still building."
The Celtics made a late run after the 76ers took a 100-88 lead on a reverse layup by Holiday with 4:19 to go.
"We had a lot of heart coming down the stretch," Holiday said. "We executed a lot of plays and we got a lot of stops."
Boston closed to 100-94 on a short jumper by Jason Terry, one free throw each by Garnett and Pierce and a field goal by Pierce. Young stopped the run with a short turnaround hook shot with 1:44 remaining, but Pierce made the next two baskets and the Celtics had a chance, trailing 102-98 with 26 seconds to go.
Turner was immediately fouled and sank both free throws. Then he converted a dunk with 17 seconds remaining for a 106-98 lead that ended Boston's last hope.
"Last year we took them to Game 7 (of the conference semifinals) and the organization got the right unit around us to keep helping us progress and we are not intimidated," Turner said. "We want more."
The Celtics scored the first five points of the fourth quarter to trim Philadelphia's lead to 83-79. Garnett made a jumper and Terry connected on a 3-pointer.
The Sixers responded with a 10-0 run to take a 93-79 lead with 8:21 left. But the Celtics scored the next seven, making it 93-86 when Terry sank a 17-footer.
The 76ers carried a 12-point lead into halftime and increased their advantage to 73-58 when Wright was fouled attempting a 3-point shot and made all three free throws with 5:46 to go in the third.
Then the Celtics went on a 7-0 run on a jumper and two free throws by Brandon Bass, two more free throws by Pierce and another by Bass. That cut the lead to 73-65.Terry's 3-pointer with 56 seconds left in the third quarter made it 79-72, but Turner scored Philadelphia's next four points for an 83-74 lead.
"I said, 'Can we stay connected and trust each other through adversity?'" Collins said. "That's what I kept saying to them, and we did."
NOTES: Holiday had seven turnovers. "Some of his passes, he got a little too much zip on them," Collins said, "but I want the ball in his hands." ... The 76ers kept beating the Celtics down court and outscored them 56-38 in the paint.