Santo's most recent start against Florida State League hitters saw him yield just two hits over eight shutout innings on Monday while striking out a season-high seven batters and walking no one.
Daytona won the game, blanking Vero Beach, 2-0.
"I thought it was my best start this season," Santo, now 6-4 on the year, said through teammate and translator Jesse Estrada.
"My slider and sinker were working well."
The 23-year-old Santo, listed as 6-foot-3 and a generous 190 pounds, needed 86 pitches to get the win. The Cubs acquired Santo from San Diego last summer in a trade that sent reliever Scott Williamson to the Padres.
"He had great stuff," Daytona manager Jody Davis said of Santo after the game. "Probably the best stuff I've seen from him this season. He's been ahead in the count much more than in the past. He didn't throw too many (pitches) early, and he's had an outstanding breaking ball.
"He is challenging guys and they are getting themselves out."
Over his last three starts, Santo has allowed just four earned runs on 13 hits in 21 innings of work, picking up the win in two of those three outings.
Santo, described by his coaches as a pitcher who has the talent to succeed and having only lacked the consistency to live up to his potential, throws a fastball routinely in the mid-90's and had been struggling to control his secondary pitches – something he has improved on as of late.
"There has never been a doubt about his stuff," Daytona pitching coach Rich Bombard said. "It's always been a question of command and being able to pitch off his fastball to set up his slider and changeup. He just threw strikes, stayed down in the zone, and was ahead in the count."
The move back to the rotation has actually helped the young hurler and his recent success. He has gone from a plus-six ERA to a 4.44 mark overall this season in five outings since moving back into the rotation.
"He's really thrown the ball well in these last three starts," Bombard said. "When you're starting, you know you're going to get the ball every five days and get your innings. The only way you are going to get better is to pitch.
"He's taken advantage of the situation."