Orlando pulled down the rebound on a Detroit miss, but Redick fired an air ball from 3 on the other end, which was corralled by Detroit.
Bynum was fouled with less than 10 seconds left and got 1 of 2 free throws to make it 104-100.
Nelson was fouled on a 3-point attempt. He made 2 of the first 3, but the third rattled out.
During a scramble for the rebound, the Magic got off three attempts that would have tied it, but came up empty as time expired.
The Pistons took a 10-point lead into the break, but it was Redick who was the star of the first half.
Redick scored 16 of the Magic's first 18 points to start the game, and knocked down 6 of his 7 attempts from beyond the arc as Orlando took a 32-29 lead.
The rest of the Magic's lineup struggled to support him offensively, though, as Detroit responded with a 15-0 run to retake control. Redick was 7 for 10 from the field in the opening 24 minutes, compared to 9 for 33 for the rest of his teammates.
Redick said he hopes the Magic keep a positive mindset as they begin a five-game road trip beginning Monday at Brooklyn.
"It just seems like it's getting more and more frustrating," he said. "The way we're losing is tough. But we can control our mindset, our attitude, our perspective over these last nine games before the break. We have a chance to use this road trip to get better, and we will."
The Pistons get one day off before hosting Milwaukee on Tuesday.
Frank said ending the road trip with a win was big.
"It's really great," he said. "We had a very tough loss after being up 17 in Chicago, (and) a very disappointing performance in Miami where we underperformed. Today, even though it wasn't perfect, the spirit was. Great collective team win. Great fight.
"I think our guys showed some great resolve and I think it's good to finish the trip on a positive note."
Notes: Davis received a technical foul with 8:33 left in the third quarter. It was the fourth straight game he has received a technical and is his fifth of the season. ...The Pistons earned just their fifth road win of the season, improving to 5-16.
Follow Kyle Hightower on Twitter at http://www.twitter.com/khightower