The Wolves were within two points early in the second half before Medlin scored six straight and Davis took over -- his points the most by an Aggies player this season.
Davis made 9 of 11 shots, including three 3-pointers. He had been averaging 2.2 points.
Aggies players had patches with Danny Berger's number, 12, stitched onto their uniforms, and signs read "We Love Danny" and "Welcome Home."
The 22-year-old Berger had been discharged from a Salt Lake City area hospital earlier Saturday after having a small defibrillator installed under his skin in his chest. He hopes to play again though it will be weeks before he has a chance to begin that comeback attempt.
The raucous Dee Glen Smith Spectrum crowd chanted his name and signs praised longtime assistant trainer Mike Williams as "fantasy trainer" for saving Berger's life after he went into cardiac arrest.
Spencer Butterfield started in Berger's place and finished with 10 points, including a 3-pointer that gave the Aggies (5-1) an 11-8 lead and launched a 16-5 Utah State run.
Andy Avgi led Division II Western Oregon (6-3) with 15 points, and Nelson Kolton added 10.
Utah State led 38-31 at halftime thanks to a 16-4 edge on points in the paint and defense that held the Wolves to 38 percent shooting.
A 3-pointer by Devon Alexander cut Utah State's lead to 43-41 but the Aggies went on an 8-0 run, with three straight baskets by Medlin.
Then Davis took over. The 6-2 guard had been averaging 2.2 points but had already matched his previous career high of eight points by halftime.
As the clock wound down in the blowout victory, the crowd again chanted "Danny Berger, Danny Berger."
Berger shook hands with opposing players afterward before heading to the locker room.
The game was Utah State's first since an 80-78 overtime road victory over Santa Clara on Nov. 28. Wednesday's matchup against Brigham Young was postponed because of Berger's health scare. It has been rescheduled for Feb. 19 in Provo.
Berger entered the arena just after his teammates ran onto the court, wearing his letterman's jacket and his left arm in a sling because of the defibrillator. He flashed a wide smile at the standing ovation and the signs welcoming him back.
Berger, his father and Williams met with the media before the game, recalling the scene before, during and after the incident Tuesday afternoon on the same floor. Berger called his recovery a "miracle" and was excited to be back in Logan but was understandably tired.
"I'll be all right. I won't be running up and down the court," said Berger, who went to high school in Medford, Ore., and was averaging 7.6 points and 3.6 rebounds as a starting forward for the Aggies.
He acknowledged it would be emotional, even though he doesn't remember much about the incident, except feeling dizzy as if he had stood up too fast.
"To be out (of the hospital) feels great," he said. "It's such a blessing to be alive and to have another chance. I'm thankful for a lot of people."
Williams did CPR then used an automatic defibrillator on Berger to get his heart working again. Berger was taken to a local hospital then flown to Intermountain Medical Center, where he was listed in critical condition until Thursday. By Friday he was on a treadmill as doctors tested his heart.
Berger couldn't say whether he would be ready for the BYU game, after all, until Tuesday his most serious health problem had been a mild concussion and sprained ankle.
His family and his second family at the Spectrum were just glad he was alive.