CINCINNATI -- The Giants hoped Kyle Harrison would be able to feed off the positive energy generated by Blake Snell’s first career no-hitter and continue an impressive run from San Francisco’s rotation, but the 22-year-old rookie hit a wall on Saturday night.

Harrison was rocked for a season-high six runs on six hits over 3 2/3 innings as the Giants fell to the Reds, 6-4, to even their three-game series at Great American Ball Park.

Harrison had allowed only two runs over 17 innings (1.06 ERA) with 20 strikeouts over his previous three starts and he was pitching on an extra day of rest, but his velocity was noticeably down against the Reds. Seven of his 34 four-seam fastballs registered below 90 mph, a significant dip from his season average of 92.7 mph. His slurve and changeup also lacked their usual zip, leaving him without much margin for error in the hitter-friendly ballpark.

“I was feeling good in the ‘pen,” Harrison said. “I maybe threw some, and I was like, ‘Eh, that’s not coming out as well.’ But I didn’t think about it too much. Really, the only time I thought about it was when I checked the velo and saw it was down and saw an 89 [mph] or something. It wasn’t the best day in terms of feeling good, but you’ve got to still compete and get after it. I didn’t compete as much as I would like to today.”

Without his best stuff, Harrison ultimately struggled to keep the Reds in the yard. He gave up a career-high-matching four homers, including a pair to Tyler Stephenson, and departed with the Giants trailing, 6-0. It marked only the second time Harrison has failed to complete four innings in 19 starts this year.

“He pitches with better velo sometimes,” manager Bob Melvin said. “At times, he’s been able to pitch when it hasn’t been great. He was just behind a lot today, and I don’t think his breaking ball was as sharp as we’ve seen it either.”

Harrison has never thrown more than 113 innings in a season since he was drafted by the Giants in the third round of the 2020 MLB Draft, but he’s on track to easily eclipse that mark this year. He’s already at 101 1/3 innings with two months to go in the regular season and will be counted on to hold down a rotation spot moving forward, especially now that the Giants have traded veteran right-hander Alex Cobb to the Guardians.

Despite the mounting workload, Harrison expressed confidence that he’ll be able to keep his arm fresh and continue to pitch meaningful innings for the Giants down the stretch.

“100 percent,” said Harrison, who has a 4.09 ERA this season. “You’ve got to take it start by start. I didn’t show up today. I didn’t do all the things I needed to do. It’s tough. I’m going to try to flush this one. I’m obviously pissed off. It sucks to put your team down in a hole that early. That’s just a tough day. I’m going to chalk it up to that and flush it and move on to the next one.”

After watching Snell no-hit the Reds in Friday night’s series opener, the Giants found themselves struggling to touch All-Star right-hander Hunter Greene, who struck out 11 and allowed only one hit -- a fourth-inning single to Michael Conforto -- over six scoreless innings.

The Giants didn’t get on the board until Matt Chapman hit a Little League home run in the seventh, when he doubled and came home on a pair of errors by TJ Friedl and Elly De La Cruz. A trio of solo shots by Conforto, Jerar Encarnacion and Chapman cut the deficit to two by the top of the ninth, but it was too little, too late for the Giants (55-57), who once again missed a chance to climb back to .500 for the first time since they were 29-29 on June 1.

“We didn’t do it tonight,” Melvin said. “We just move on, win a series tomorrow. I think if we win the series tomorrow, we’ll feel pretty good about what we’ve done here.”