He struck out 11 in six innings in a 5-3 victory over the Rockies on Friday night. He allowed three runs and six hits and walked one.
The Rangers' Josh Hamilton left the game after seven innings with a tight left groin. He's day to day.
The Rockies' Michael Cuddyer left in the sixth after a Darvish fastball hit him on the right hand. He suffered a bruise.
"It didn't seem like I had that many strikeouts," Darvish said through an interpreter. "But just the way me and (catcher) Mike Napoli, the way we worked together tonight, some of the great pitch calling that he made for me, and the way I was able to pitching comfortably, that all led to the 11 strikeouts."
In the second inning, Helton led off with a double, and Giambi followed with a two-run home run.
"I threw a strike, and he hit a home run, which I deserve to get hit in that situation," said Darvish, whose ERA is 3.60. "Giving up a home run to a hitter like Jason Giambi, I'm kind of honored by that."
Darvish threw 98 pitches and got in trouble in the sixth inning. He gave up a leadoff single to Fowler, and after a stolen base, wild pitch and two outs, he allowed an RBI single to Helton, a double to Giambi and hit Cuddyer. A flyout ended the inning.
Darvish said he didn't get tired.
Rangers manager Ron Washington said Darvish didn't seem fatigued, as he continued to show good velocity.
"He had a good four-seam fastball working. He was moving it around, threw some good sinkers, went through some pretty good hitters, especially those left-handers," Washington said. "Each time he's taken the ball, he's gotten better."
Darvish will make his final start before the regular season Wednesday in Frisco, Calif., against the Rangers' Double-A team.
Rockies starter Jhoulys Chacin allowed five runs and nine hits in 61/3 innings. He struck out three and walked one.
Cuddyer won't play Saturday, but is expected back in the lineup Sunday. ... LHP Jason Outman has made the Rockies as a reliever. ... Before the game, Rockies manager Jim Tracy announced 49-year-old left-hander Jamie Moyer made the starting rotation and will start the second game of the season April 7. Moyer will follow RHP Jeremy Guthrie and precede RHP Juan Nicasio and Chacin, who will pitch the home opener April 9 against the San Francisco Giants. With a day off on April 10, the Rockies will open the season with a four-man rotation. Left-hander Drew Pomeranz will join the rotation and make his first start April 15. ... The Rockies optioned Pomeranz and RHP Guillermo Moscoso to Triple-A and reassigned C Wilkin Castillo and OF Andrew Brown to minor league camp.