Castro blocked the inside half of the plate and tagged Ackley just before he slid home. The umpires called for a Crew Chief Review to determine if there was a violation of the new collision rule, but the review showed no violation and the out call was confirmed.
The out was the second of the inning for Seattle, but the Mariners followed with six consecutive hits -- including five doubles -- to score seven runs in that frame and break open a 10-1 lead.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.