The Mariners' record fell to 23-36 and dropped them a season-high nine games out of first place in the American League West.
Snell (0-5, 5.89 ERA) retired five of the 14 batters he faced and was unable to make it through the second inning, when the Rangers batted around and scored six runs to put the third game of the four-game series out of reach.
"You come out and score two runs and feel like you're going," Wakamatsu said, "and then give it right back. The six runs in the second deflated us a little bit at that point."
Snell began falling behind in the count and the Rangers were swinging when he had to throw strikes.
"We talked about why Cliff Lee was so successful the other day," Wakamatsu said. "We talked about him getting ahead with first pitch-strikes. Ian was 5-for-15 and when Ian got hurt, most of his pitches were up in the zone."
Snell was one out away from ending the second inning before throwing an 0-and-2 slider to Michael Young that was drilled into center field for a run-scoring single, the first of four consecutive hits -- capped by Josh Hamilton's two-run home run to right-center.
"To tell you the truth, I don't think any pitch would have made any difference," said Snell when asked about the game-changing (at the time) pitch to Young. "He got the bat on the ball and it found the spot in the outfield.
"That's how it was all night for us. Besides the two home runs, they found places to drop the ball in. They are a good hitting team, and they are hot right now."
Unlike his previous outing, when he left Safeco Field in a huff after losing to the Angels, Snell took the high road on Wednesday.
"Nobody can blame [this game] on this team, but on myself," he said. "I can take this on myself. I just have to keep my head held high and keep going after it. It's still a long season and things can turn around."
But he might have to turn it around out of the bullpen.
There appears to be a good chance that left-hander Luke French will be starting five days from now in St. Louis.
He replaced Snell in the second inning and took the game into the eighth inning, allowing seven hits and four runs.
Could he be a starting candidate going forward?
"Possibly," Wakamatsu said. "This was his first long outing (since being recalled from Triple-A Tacoma on June 6) and we were able to stretch him out, which gives us that option. He looked more refined, in better shape and his delivery was cleaner than last year."
Snell isn't sure what his next assignment will be, but he seems prepared for anything.
"I'm not really too worried about it," he said. "Maybe it's a lack of confidence, but I will keep my head held high and just keep getting after it. That's all I can do. I'm not going to sit and complain about it."
Snell was staked to a two-run lead in the first inning, when a walk and back-to-back two-out doubles from Jose Lopez and Josh Wilson off C.J. Wilson got the Mariners off and running.
Or so it seemed.
"I thought we were going to have a good day," Wakamatsu said. "We swung the bat well [in the first inning] but nothing from that point forward."
The Mariners managed four baserunners from the second through eighth innings, and although they loaded the bases in the ninth, it was another quiet night for most of the hitters.
Wilson entered the game with hits in 17 of his past 20 games, batting .342 during the stretch, a hitting binge that prompted Wakamatsu to bat him fifth, and the shortstop responded with two hits.
Prior to Wednesday night, the highest the shortstop had been in the lineup this season was sixth. He also has batted seventh, eighth and ninth.
But Snell, who said after his previous start that he wasn't "Superman," went out and proved it against the Rangers
After scoring two runs in the bottom of the first to wipe out Seattle's lead, the Rangers delivered a knockout blow in the second.
How it affects Snell's status in the rotation remains uncertain, but French received most of the accolades after the game.
"I thought Frenchy did a good job of saving our bullpen," Wakamatsu said. "Most of the damage was against left-handed hitters, but other than that, I thought he attacked the zone and didn't walk anybody."