TORONTO -- After battling through his first full season in the big leagues last year**,** Lucas Giolito wanted to hit the reset button this offseason and start fresh ahead of this year.

With some help from an old friend, the 24-year-old right-hander has embraced a new delivery this season, the result of a change in his arm action and his mindset. The differences made on the mound by Giolito have helped not only his confidence, but also his ability to not let minor setbacks or mistakes snowball into others, which was apparent in Sunday’s 5-1 win over the Blue Jays.

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In the first inning of the Mother’s Day matchup, Giolito matched the total number of hits he gave up in his entire last outing, allowing three knocks before recording his second out. But from there, it appeared as though the right-hander found the new mindset that his altered arm action is responsible for, retiring 18 of the final 20 batters he faced, allowing only a leadoff single in the second and a walk in the fourth.

“It makes it a little bit easier to pitch, because it’s easier to be on time,” Giolito said before Sunday’s outing. “If my arm is on time, I’m synced up, then my misses are probably going to be smaller. So it puts me more at ease.

“I’m not out there worrying about throwing strikes or worried about things snowballing, because I know that I have the baseline of what I know I can do as a pitcher, and that’s fill up the zone with quality pitches.”

The difference in Giolito this season has been incredibly evident, and the White Sox couldn’t be happier with the results.

“Early on in his career with us, that first inning could have unraveled,” White Sox manager Rick Renteria said. “He hasn’t been having those types of outings. Right now, he’s very focused and very trusting of who he is.”

Giolito finished seven innings of one-run ball, and matched his season high with eight strikeouts. His stellar start was backed by a five-run fourth inning from the visitors, highlighted by home runs from Yonder Alonso -- his sixth of the year, a two-run shot -- and Tim Anderson, a three-run homer for his eighth of the year.

Early in the game, Giolito and catcher James McCann realized that the fastball-changeup combination that allowed him success in his last start against Cleveland -- in which he threw 7 1/3 scoreless innings -- was not going to work against the Blue Jays, and they altered their plan. According to Statcast, the hurler threw only 45 fastballs among his 105 pitches, going to his slider and curveball a total of 31 times.

“Once you get on the field, you’ve got to trust what your eyes are telling you,” McCann said. “His last outing … he threw like three breaking balls, and honestly I thought [Toronto] had a decent approach to that. They were looking to stay on the fastball, really go out of their way to stay with his changeup, and we started mixing in more breaking balls than he’s used in the past.”

Added Renteria: “Obviously, he changes the sequencing a little bit to get the hitters off his fastball, but still used his fastball extremely well to establish it, and then he used everything else in his sequence of pitching.”

With all of the success Giolito found on Sunday, the most impressive thing was his ability to not let the game get out of control when he ran into trouble early.

“Those are some of the things I think experience, time and trust start to allow you to be able to work through,” Renteria said. “You don’t allow those moments to take a hold of you and shake you. He kept his composure and did a really nice job. I think it’s the maturity. This young man’s done a lot to put himself in a better place, and it’s noticeable.”

Though the White Sox are reaping the benefits of Giolito’s adjustments now, the changes were made after times got tough last year. His confidence had waned, and he was ready to welcome advice he had previously paid no heed to. So the 6-foot-6, 245-pounder went to his former mentor looking for help and ended up with his new delivery.

“It was kind of weird,” Giolito said. “I didn’t go into the offseason thinking, 'My arm action’s too long.' I basically went to my pitching guru, Ethan Katz -- he was my pitching coach in high school and now he’s the [assistant pitching coordinator] for the San Francisco Giants -- and I obviously had a rough season last year, so I said, ‘I know you’ve suggested things in the past and I never really bought into it, but whatever you’ve got for me, I’m doing it.’”

Taking Katz’s advice, Giolito began a weighted ball program specifically focused on a few movements, and within two weeks of trying it out, his arm action shortened without any conscious thought.

“I never had to consciously think about what my arm was doing,” Giolito said. “It was a result of the work I was putting into the weighted ball program, essentially throwing weighted balls against the wall.

“I don’t know the science behind it, but if your arm is too long and you’re not on time, it’s a weighted ball, so it’s not going to feel good. It forces you to be quick, compact, short, and it just kind of took over.”