Jackson was rocked for the second straight outing as the Cubs scored eight runs against him in four innings en route to a 10-5 win Sunday afternoon.
The D-backs have now dropped three straight after winning their two prior series, as well as the first game of the set with the Cubs. They continue their 11-game road trip Monday in Houston.
"Today was just a day we got flat out beat," D-backs center fielder Chris Young said. "Houston's not going to take it easy on us so we've got to go in there ready."
The good news for the D-backs is that Alfonso Soriano will not be flying with them to Houston. After going 0-for-3 in the opener of the series, the Cubs left fielder bludgeoned the D-backs the next three days.
Sunday he was 3-for-4 with a pair of homers and four RBIs.
"You can tell the confidence was growing as the series went on," D-backs manager A.J. Hinch said of Soriano. "It seemed liked every time they had multiple runners on he was coming to the plate and he delivered. He was definitely the key to the series. He was the headliner from this series."
Soriano homered in each of the last three games giving him four for the series and he drove in 10 runs in those games, something he's done in a three-game stretch just one other time in his career.
The D-backs tried different methods to get him out, but none seemed to work.
"He's hot as can be," Hinch said. "We pitched him a little tentatively earlier in the series. He hit everything. He hit fastballs away, he hit a breaking ball out, a first-pitch breaking ball, a pitch in from [Daniel] Stange. He's red hot."
Jackson, by contrast, is not. In his last two starts he has allowed 18 runs on 22 hits in just 6 1/3 innings.
At least in his previous game against the Rockies he could say that some of the Colorado hits were not well struck. Sunday, though, the Cubs didn't have any cheapies.
"It's just locating my fastball," Jackson said. "You have to be either in or out and not right over the dish of the plate and right now a lot of pitches are right over the middle of the plate. It's hard to throw the ball down the middle and get outs. Even when I'm ahead in the count I'm missing with pitches right down the middle -- with pitches that shouldn't be right down the middle -- and they're getting hit like they're supposed to."
Jackson (1-3) had to think for a minute when asked if he could remember another stretch like this during his career.
"It's been a while," he said. "The last time I got hit like this is from tipping [pitches], but I don't think that's the case right now, I think it's just missing with pitches over the middle, but it's definitely been a while since I've had games like this back-to-back like that."
Hinch wants to make sure that it does not extend to a third start.
"Two starts in a row, in one way it's worrisome because it's two starts," Hinch said. "But at the same time it's only two starts. He's a different pitcher when he falls behind, guys can dial it up and hit his fastball. He needs to execute pitches to get into favorable counts to where he threatens the hitter. We'll get him to regroup and get back out there in five days."
The D-backs, however, don't have five days to get going in a better direction. They are in a stretch consisting of 20 games in 20 days.
"The Cubs outplayed us," Hinch said. "It's pretty simple. They outhit us and they outpitched us. It's disappointing because of the opportunity we had as well as we were playing coming in. We just didn't play good enough. We need to regroup in Houston and make it a better outcome."
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.