Young led off the first inning with a homer for the sixth time this season, and Valverde survived a harrowing ninth to help Arizona beat the Florida Marlins 5-4 Thursday.
Valverde walked two and faced NL batting leader Hanley Ramirez with two out.
"I said, 'Oh man, we've got the MVP versus the best closer in the game,"' Arizona second baseman Orlando Hudson said. "Fortunately my man Valverde did his thing, like always."
Ramirez fouled out, giving Valverde his 37th save in 43 chances. The NL West leaders won two of three in Miami, and they've taken eight consecutive series.
"Move on to the next one," said manager Bob Melvin, whose team plays in Atlanta this weekend. "Don't think too much about the last one."
The Diamondbacks won for the 19th time in their past 24 games, and they improved to 27-16 in one-run games. They went 6-1 against Florida this season.
Young's homer was his 22nd, tying tied the Arizona rookie record set by Travis Lee in 1998. Four times Young has homered on the road as the game's first batter.
"It feels great, because it does help get some kind of momentum going," Young said. "Any kind of hit is a plus, not just a home run."
Livan Hernandez (9-7) shook off a case of nausea to pitch seven innings. He gave up three runs in the first, then allowed only one run over the next six innings.
Hernandez said he threw up in the bathroom between the first and second.
"I think I ate too late today," he said. "After the first inning, I felt much better."
The right-hander struck out none but walked only one, and he also had two hits and scored a run.
Clinging to a 5-4 lead, the Diamondbacks turned double plays in the fifth, sixth and seventh. The last of those came with runners at the corners and was started by Hudson, who made a nifty pickup when Ramirez's sharp grounder took a bad hop.
"A great play," Ramirez said.
"It took a little hop, plus he scorched that ball, too, so I was just hoping to knock that ball down," Hudson said. "But it ended up finding its way into my webbing, and we ended up turning a pretty good double play."
NL batting leader Ramirez singled and homered earlier, extending his hitting streak to 13 games. That's the longest of his career, and the longest active streak in the major leagues.
Mike Jacobs hit a two-run homer for Florida, his 10th. He's 11-for-22 since an 0-for-33 slump.
Mark Reynolds hit his 10th homer for Arizona's final run in the third off rookie Daniel Barone (0-1), who made his second major league start and needed 89 pitches to get through four innings. He allowed five runs, four earned.
"You just have to put it behind you and do better next time," said Barone.
Arizona scored twice to take the lead for good in the second. Hernandez singled, took third on a double by Young and came home on a single by Hudson. When Hudson stole second, catcher Miguel Olivo bobbled the ball as he tried to throw, and Young dashed home with an unearned run, barely beating the tag for a 4-3 lead.
"I just took a chance," Young said. "If you get thrown out by a lot you look dumb, and if you're safe it makes you look good. It's just a gamble, and it could have gone either way."
Olivo strained his groin in the collision with Young and left the game. His status is day to day.
Ramirez's 22nd homer in the fifth cut Arizona's lead to 5-4.
- Marlins rookie center fielder Alejandro De Aza threw out Hernandez and Young trying to stretch singles into doubles.
- Jacobs became the seventh Marlins player to reach double figures in homers.
- Marlins LHP Dontrelle Willis pinch-hit for the second time this season in the fifth inning and flied out.
- Hernandez has allowed 27 homers this year.