"We've got some proven veteran big league hitters in here and they've made a big difference, but we've also got some young guys that have continued on the path and swung the bat well," Mariners manager Eric Wedge said.
The Rockies also smacked two long balls, theirs coming off the bats of Kent Matthes and Nolan Arenado, who hit his third in as many days and fourth of the spring.
Staring for the Mariners, Jon Garland threw two scoreless frames while Colorado's starter, Juan Nicasio, allowed three earned runs over his three innings of work.
Seattle took the lead in the bottom of the first inning when Wells drove home Kyle Seager. Raul Ibanez extended the Mariners' lead two frames later when he drove a ball into the grass in right field for a solo shot. Seager delivered the other long ball of the day, a three-run shot in the fifth.
"I wasn't sharp. I threw a lot of balls. That's what happens when you get behind hitters," Nicasio said. "Last time, I threw for strikes. But today it changed. A couple changeups up in the zone, a hanging breaking ball."
Up next: The Mariners will get their first off-day of the spring on Tuesday before remaining in Peoria on Wednesday to host the Brewers at 12:05 p.m. PT. Scheduled to pitch against Milwaukee are Blake Beavan, Erasmo Ramirez, Josh Kinney and Charlie Furbush. Fighting to earn a spot in the bullpen, Kameron Loe, who has yet to give up an earned run in four spring innings, will also take the mound.
Tyler Emerick is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.