PHOENIX -- Ryan Roberts felt his upper body moving ahead of his legs and frantically tried to get them in synch, thinking the entire time: Don't fall.
Arizona's tattooed third baseman managed to stay upright until one final lunge, providing the capping highlight in a high-scoring, what-will-happen-next series.
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"I was so gassed," Roberts said after the eighth inside-the-park homer in franchise history. "It doesn't seem like that far around the bases, but it is when you're running that hard. I'm just glad I didn't fall over."
Arizona opened the three-game series with a 7-1 win behind Aaron Hill's cycle, the fifth in franchise history. Seattle outlasted the Diamondbacks in the middle game, winning 12-9 in 10 innings.
The finale featured plenty of momentum swings, hard-hit balls and one mad dash around the bases by Roberts.
Miguel Montero hit a two-run homer and drove in four runs in all. Justin Upton had a three-run shot to end an 82 at-bat homerless drought. Hill became the first Arizona player to double and homer in three straight games. Jason Kubel and John McDonald each hit a solo shot, and Roberts had his first inside-the-parker to give the Diamondbacks six homers in a game for the third time in franchise history.
Arizona finished with 10 extra-base hits, its most since 2009 against Colorado, collected 16 hits overall and batted around in the fifth inning while chasing Jason Vargas (7-7). The Diamondbacks scored 30 runs in three games against the Mariners, their most since scoring 32 against Milwaukee from Sept. 25-27, 2001.
"We didn't quit and kept putting runs in the board," Diamondbacks manager Kirk Gibson said. "Ryno's inside the parker was exciting, Miggy had a great day. J-Up got back on track. It was a pretty good team effort."
The Mariners couldn't keep up.
They scored five runs against Trevor Cahill (6-5) in the third inning, hit double digits in runs for the second straight game and had 14 hits.
It wasn't enough to overcome Arizona's barrage of homers, including five against Vargas to match a team record.
"They were really squaring up the ball against us," Mariners manager Eric Wedge said.
A short turnaround from Tuesday's late game didn't hamper the lineups one bit in the series finale.
Hill got it started with a solo homer off Vargas in the first inning to extend his home hitting streak to 13 games, and Kubel followed with a homer of his own.
Hill added a double in the third inning, becoming the first player to homer and double in three straight games since Tampa Bay's Evan Longoria from June 25-27, 2008, and first in the NL since Aramis Ramirez accomplished the feat with the Cubs from July 17-19, 2005.
A day after scoring six runs in the fifth inning, the Mariners put up another big number in the third against Cahill. John Jaso had a run-scoring double to the corner in right, Wells followed with a two-run single and Seager made it 5-2 with a drive to right.
Vargas couldn't hold the lead, though, yielding a two-run homer to Montero and a solo shot to McDonald in the fourth that tied it at 5.
Upton broke the tie with a never-a-doubt drive -- estimated at 457 feet -- to the second deck in left-center in the fifth inning, his first since May 23.
Roberts added a run-scoring single off Shawn Kelley and McDonald followed with a run-scoring double to make it 10-5.
Vargas allowed 10 runs and nine hits in 4 1/3 innings, the fourth straight start he's given up at least four earned runs.
"They swung the bats well," said Vargas, who joined Jamie Moyer in 1988 and 2006 as the only Seattle pitchers to allow five homers in a game. "You can't take anything away from them, but I gave them some opportunities. They didn't miss any of them."
The Diamondbacks still weren't done.
Montero hit a two-run single in the sixth off Lucas Luetge and Roberts brought the crowd to his feet, sliding headfirst to beat the throw home for his first circle-the-bases homer. Roberts' fifth of the season put Arizona up 14-6 and led to a curtain call and lots of heavy breathing on the bench.
"It took me a couple of innings to catch my breath and realize how special it was," he said.
The offensive outpouring allowed Cahill to win his fourth straight start despite not having his best stuff.
The right-hander allowed six runs and nine hits in six innings after giving up two earned runs over 23 1/3 innings in his previous three games.
"It's good to get a win any way you can get it," Cahill said.
- The Diamondbacks extended their rookie league affiliation with the Missoula Osprey by four years through 2016.
- Gutierrez's homer was his first since May 25, 2011, at Minnesota.
- The Diamondbacks have a day off before opening a three-game home series against the Chicago Cubs on Friday. Left-hander Joe Saunders will pitch for Arizona after going 1-2 with a 2.63 ERA his previous four starts.
- The Mariners also have a day off before RHP Kevin Millwood pitches against the Padres on Friday. He had a no-decision his last start, allowing three earned runs in five innings against San Francisco after participating in a six-pitcher no-hitter the outing before.