PHOENIX -- For a last-place club like the D-backs to win a game -- let alone avoid a series sweep -- against a first-place club like the Reds, a few things need to go just right.

Tuesday through Thursday at Chase Field, not much did.

So behind a sloppy defense (four errors) and a regressing bullpen (16 runs in nine innings), Arizona lost each of its three matches with Cincinnati, the brooms coming out from the closet following Thursday's 9-5 finale.

"We played a very good team, and they're on a roll," interim manager Kirk Gibson said. "They capitalized on the little mini mistakes or the little openings that we gave them, and we played pretty decently -- we scored some runs -- but they outplayed us. You can look right over there [at the Reds] to see how far we've got to go."

The D-backs have now lost four straight games and six of seven to even their August record at 9-9.

In their 75th loss of the season, the names were Rusty Ryal and D.J. Carrasco, but the story was largely the same. The Reds' five-run eighth inning began with two outs, when Ryal charged in from left field on Jay Bruce's catchable liner, but let the baseball fall to the turf.

"I dropped it," Ryal said, shrugging. "I didn't make the play."

Gibson seemed more perturbed by the bullpen's step backward, Carrasco and Jordan Norberto, allowing the next five Reds to reach safely.

"We've got to pick Ryal up," the skipper said. "Even though we made the error, we need to be better at stopping those things."

Unlike Wednesday night -- when the D-backs momentarily held a lead -- they were climbing upward throughout.

What appeared to be a pitchers' duel in the making between starters Joe Saunders and Cincinnati lefty Travis Wood (4-1) through three easy innings changed swiftly in the fourth. Saunders (7-13) allowed a pair of long balls on a half-dozen pitches.

With two Reds aboard, Ramon Hernandez pulled a first-pitch Saunders fastball into the left-field seats and Jay Bruce, the very next batter, struck a 3-1 heater into the right-field bleachers.

Just like that: 4-0.

"I should have known that Ramon was going to be aggressive with a runner on," said Saunders, who has lost three straight starts, but was pitching on Thursday with flu-like symptoms. "It wasn't a bad pitch; it was just the wrong pitch."

Until Mark Reynolds mashed his 27th home run, a solo shot, in the fifth, the D-backs had done little against Wood.

Arizona did manage to bring the potential game-tying run to the plate in the seventh after Chris Young's leadoff double and Reynolds' walk. But the first of four Reds relievers, Logan Ondrusek, retired Ryal and John Hester on six pitches.

"That's hard," Gibson said. "That takes it out of you when you get a guy out there and you don't move 'em over, you don't get 'em in."

By the time the D-backs were able to do some damage -- plating four runs, including Young's three-run shot, in the eighth -- their deficit had been stretched from three to eight.

"Even though we didn't win any games in this series ..." said Young, in search of something, anything positive. "You know, actually, never mind. We played a couple of bad games in this series."