Reggie Jackson was also on fire, racking up 29 points for Oklahoma City. The 23-year-old was 10-of-17 from the field.
After a win over Fenerbahce Ulker in Istanbul on Saturday, Scott Brooks' team carried on its preparation for the regular season with a fast start.
OKC led 25-22 after one quarter, but the 76ers rallied for a 51-48 lead at halftime.
OKC outscored the Sixers 35-23 in the third quarter to take control.
Brooks was proud of the way his players conducted themselves in Manchester and felt they put on a good show.
“I thought the guys did a great job at moving the basketball,” he said. “We distributed the ball fairly well, but there are still one or two things we have to go back to the drawing board on to improve.”
The Thunder coach was particularly excited about the future for big man Steven Adams.
“I think he is going to be a very exciting player for us,” Brooks said. “What I love about him is that he works extremely hard each day and has the mentality that we all have. We never take days off.
“If you have that in your players, they are going to improve and they are going to improve at the pace you want them to.”
The Thunder returns to action Oct. 15 at Chesapeake Energy Arena for a preseason game against the Denver Nuggets.