PHOENIX -- It's a role that's tough to get used to, but Chad Tracy has been forced to acclimate to pinch-hitting the last few years.

On Friday night at Chase Field, there was no bigger hit than Tracy's pinch-hit two-run double in the eighth inning that sent the D-backs to a 6-4 victory over the Rockies.

With the game tied at 4, Tracy stepped in with two runners on base, and he smacked a line drive down the right-field line on the sixth pitch of the at-bat to set up the win for the D-backs (80-80).

"I don't think you can ever really get used to pinch-hitting," Tracy said. "You come from the bench, where everything is relaxed and you don't have any pressure on you, and then within a matter of a couple minutes, you're thrown in a situation where the game is on the line."

Tracy has worn out Rockies pitching this year, going 10-for-25 (.400).

He hasn't necessarily had a specific role in 2008, especially after the acquisition of Adam Dunn, who has occupied Tracy's position of first base. But Tracy has given the D-backs good, consistent at-bats since he returned from knee surgery after missing the season's first 50 games.

"I thought it was a really good at-bat," D-backs manager Bob Melvin said. "I think we're just starting to see a guy hit with his legs underneath him. And I think next year he'll be that much more healthy, and you'll start to see 'Trace' swing the bat like we're used to seeing him in past years.

"Next year a healthy Chad Tracy could be a significant piece for us."

The D-backs had overcome a three-run deficit early on. Dan Haren allowed three first-inning runs, but Arizona slowly chipped away. In the fourth inning, Justin Upton hit a 430-foot towering home run to center field.

In the fifth, the D-backs took the lead after a Stephen Drew homer and Upton's two-run triple that scored David Eckstein and Conor Jackson.

If only Upton could play all his games at Chase Field. At home, Upton boasts a .335 batting average, almost doubling his .169 season road average.

Haren surpassed the 200-strikeout mark for the first time in his career with his nine on Friday. He finished the season with a total of 206.

"It's nice," Haren said. "More guys throw 200 innings than strike out 200 guys, and I really didn't get off to a great start striking out guys this year. But my stuff got better, I think, as the year went along, and I was able to strike out a good amount of guys. It's nice hitting career highs in that and in wins. I still feel like I've got a lot of room for improvement, though."

It was an impressive year for Haren, who finished the season with 16 wins, but he probably could have had a few more early on. After his December acquisition, Haren was viewed as a solid No. 2 pitcher to ace Brandon Webb, but what it turned out to be was a staff of co-aces.

"I think he's had an exceptional year, especially at the beginning when he was kind of the hard-luck guy," Melvin said. "He comes as advertised, exactly what we thought we'd get out of him, if not even a little more. Great clubhouse presence on top of it. [He] fits in very well here. He had a good year for us."

Haren had a pretty tough first inning. After walking Seth Smith to lead off the game, Troy Tulowitzki had an RBI double. After a Brad Hawpe double, Tulowitzki scored. On the following play, Garrett Atkins hit a weak grounder between the catcher and third baseman Mark Reynolds, who was playing deep. Miguel Montero ended up fielding the grounder and throwing it to first for the out, but Haren forgot to cover home plate and Hawpe scored from second with no throw.

"It was kind of a fluky first inning, a mental breakdown by me," Haren said. "One hard-hit ball and three runs, but that's baseball.

"My stuff was actually really good today -- better than it's been the last couple times. The control was there, and I found a rhythm."

Haren allowed just one more run, in the seventh inning, on an RBI double by Joe Koshansky.

"After the first inning, he pitched well," Melvin said. "He had a good cutter today, a good split. Other than just kind of a wacky first inning there to start, I thought he pitched really well."