PHOENIX -- The Arizona Diamondbacks' first series sweep of the season should have come as no surprise, especially to the Cincinnati Reds.

Arizona rallied from a four-run deficit and beat Cincinnati 6-5 on Sunday -- the Diamondbacks' 14th win in a row against the Reds.

''I've never seen anything like it,'' said Mark Grace, whose seventh-inning sacrifice fly scored Luis Gonzalez with the go-ahead run. ''That's a good ballclub over there, but it seems we've had their number the last couple or three years.''

Arizona has won five in a row overall to move within six games of NL West-leading San Francisco and Los Angeles. The Diamondbacks have won seven of their last eight and are 35-25 since a dismal 3-11 start.

''Whenever you're way behind, sometimes you can't help but look up,'' said Steve Finley, who went 4-for-4 and hit his ninth homer for Arizona. ''But you just need to go out and try to win every day.''

Finley's three-run homer in the fifth pulled Arizona within 5-4 after the Diamondbacks watched Cincinnati open a 4-0 first-inning lead.

''I'm not trying to hit homers,'' Finley said. ''He left a changeup up over the middle of the plate and I took advantage of it.''

Kent Mercker (0-1) entered in the bottom of the seventh with Cincinnati holding a 5-4 lead. But Finley and Carlos Baerga opened the inning with consecutive singles and Mercker walked Gonzalez on four pitches to load the bases. Mercker then walked David Dellucci to tie the game 5-5, Dellucci's second bases-loaded walk of the game.

''How many did we walk today, a hundred?'' Cincinnati manager Bob Boone asked. ''We let them back in. We gave it to them.''

Chris Reitsma relieved Mercker and got Robby Hammock to hit into a force play at the plate. But Grace hit a high fly ball down the left-field line, and Gonzalez scored easily to give the Diamondbacks a 6-5 lead.

Eddie Oropesa (1-1) pitched one hitless inning for the win. Jose Valverde pitched the ninth for his seventh save in seven chances.

''For the last five days, I've been pretty happy,'' Valverde said through an interpreter. ''I'm going to keep going to the mound and do my job and do my best.''

Valverde has appeared in Arizona's last five games, saving four and winning one.

The Reds used four hits and a hit batter to take a 4-0 lead in the first against Andrew Good.

Reds starter Ryan Dempster gave up four runs on seven hits and three walks in five innings.

Sean Casey drove in two runs for the Reds, including one in their four-run first.

Notes: Arizona RHP Brady Raggio relieved Oropesa in the eighth -- his first major league appearance since June 24, 1998, when he was a member of the St. Louis Cardinals. … Only 49 of Dempster's 91 pitches were strikes. … Good surrendered more runs in the first inning alone than he had in any of his previous four starts, but bounced back to strike out the side in the second. He matched a career high with seven strikeouts over five innings. … Arizona 3B Craig Counsell, on the DL since May 7 because of surgery on his right thumb, was in Washington on Sunday for the beginning of the annual T-ball program at the White House.