The Mets plunged to a single game above .500 after Friday night's series opener, as Kelly Johnson hit a go-ahead two-run homer in the sixth and Miguel Montero tacked on a three-run shot later in the frame to help the Diamondbacks snap a seven-game slide with a 9-6 win.
Montero went 3-for-5 with four RBI to highlight the offensive outburst for Arizona, which had lost four games at home to San Francisco and three straight at Philadelphia coming in.
Ian Kennedy (6-8) labored through six innings but still wound up with the win after giving up five runs on three hits and four walks.
David Wright had his first multi-home run game at Citi Field, driving in five runs in New York's fourth loss in six games.
New York has lost 11 of 14 and is 7 1/2 games behind front-running Atlanta in the National League's East Division. The Mets are 32-18 in 50 games at Citi Field.
Taking the mound for the hosts will be Tokyo-born lefty Hisanori Takahashi, who'll make his 12th start in his 29th big-league appearance.
The 35-year-old product of the Japanese professional leagues tossed an inning of scoreless relief in his most recent outing, striking out two batters in the Mets' 8-7 loss to St. Louis on July 28.
He went seven innings in a start six days earlier in Los Angeles, dropping a 2-0 verdict to the Dodgers in spite of allowing just three hits and striking out five.
His last victory came July 4 at Washington, when he allowed five hits and three runs in five innings of New York's 9-5 holiday triumph.
Takahashi has never faced the Diamondbacks.
Arizona counters with 24-year-old rookie Barry Enright, who'll make his second start against the Mets in his sixth major-league outing.
The recent 2007 second-round draft pick was a 3-2 winner over New York in Phoenix on July 20 after allowing five hits and a run, with eight strikeouts, in eight innings.
Overall, in 29 2/3 innings, he's given up 28 hits and nine runs with 23 strikeouts.
The outing at Citi Field is his second road start and first since his June 30 debut at St. Louis, a 4-2 victory.
The Diamondbacks swept a three-game set at home over the Mets from July 19-21 and have won eight of the last nine in the series.