"He's really given us a lift in that rotation," Rockies manager Walt Weiss said of Lyles.
He originally was slated to begin the season at Triple-A Colorado Springs but wound up filling in for Tyler Chatwood after he strained a hamstring late in spring training.
"The biggest factor is his two-seamer," Weiss added. "It's something he worked on all spring, his fastball angle and pitching to the bottom of the zone, and you could see those guys beating it into the ground. He's a mentally tough kid. He competes. He goes after hitters. He's been great."
Lyles (3-0), acquired in December from Houston in exchange for outfielder Dexter Fowler, allowed one unearned run and five hits in seven innings. LaTroy Hawkins pitched a hitless ninth for his fifth save in five chances.
"As a visitor, it wasn't fun, knowing you're coming here." Lyles said. "Balls seem to carry a little further here but guys (pitchers) try to keep the ball on the ground and they can't hit it over if they hit the top of the ball. That's my approach and just try to let our great infield do their job."
The Rockies were also helped by a reversed call that produced their first run.
The game was delayed briefly a couple of times when a squirrel wandered on and off the field. The animal was eventually corraled by groundskeepers and taken away.
Kyle Kendrick (0-2) went seven innings and allowed three runs on six hits in a solid outing but could not avoid a seventh straight loss, dating to last Aug. 11. The last Phillies pitcher to have a losing streak of seven games or more was reliever Brad Lidge, who lost eight in a row over 57 appearances from April 18-Sept. 23, 2009.
"Made a mistake to Morneau," Kendrick said. "That first run. It was a replay. I guess that's why we have it, but it's frustrating when it doesn't go (your way)."
Colorado got on the scoreboard when home plate umpire and crew chief Tim Welke ruled Nolan Arenado safe on a bang-bang play at the plate in the third after initially calling him out. Weiss asked Welke to take another look at the play, and after viewing the replay, the umpire determined that catcher Carlos Ruiz had blocked the plate before he received the throw home in violation of new collision rules instituted this season to better protect catchers and base runners.
Arenado scored from first on D.J. LeMahieu's single that rolled through the right-center gap.
The reversal went into the books as a crew chief review rather than a manager's challenge.
"It's amazing how that one rule changes the game, kind of," Arenado said. "Fortunately enough, it benefited us and I guess when you're on the other side, it's probably going to rub you the wrong way a little bit."
Carlos Gonzalez opened the fourth with a single and Morneau drove a 1-1 pitch from Kendrick into the right field bleachers above the scoreboard for his third homer of the season to make it 3-0.
The Phillies didn't get on the board until the eighth. Lyles gave up a leadoff single to Cody Asche and was relieved by Boone Logan. Pinch-hitter John Mayberry Jr. reached on Logan's throwing error, with Asche moving to second. Logan then retired the next three batters, giving up a run on Jimmy Rollins' grounder and striking out Chase Utley with Mayberry on second base to end the inning.
Philadelphia has only scored three runs in its last four games.
"You're going to go through ruts in the season," Kendrick said. "You want to get out of it as quick as you can. Hopefully tomorrow we can swing it and score some runs. Things can turn quick."
The Phillies selected the contract of RHP Shawn Camp from Triple A Lehigh Valley, filling the roster spot of RHP Jonathan Pettibone, who was optioned to Lehigh Valley the night before. The Phillies will have to make another roster move when LHP Cole Hamels (left biceps tendinitis) is expected to be reinstated from the disabled list in time to start Wedneday's game at Los Angeles. Hamels is one win shy of 100 for his career. ... Rockies OF-INF Michael Cuddyer missed a second straight game with a sore left hamstring. He remains day to day. ... Arenado's leadoff single in the third inning extended his hitting streak to 10 games, matching a career best. ... RHP Roberto Hernandez (1-0) is slated to start Sunday's series finale for the Phillies against Rockies' RHP Juan Nicasio (2-0).