The previous record for a Mariners catcher reaching base to start a season was three consecutive plate appearances, done five times by different players. The club record for a player at any position remains eight by left fielder Steve Henderson in 1983.
Backup catcher Steve Clevenger got the start in Wednesday's series finale, but Iannetta will be back in the lineup for Friday night's home opener against the A's.
Yeah, Iannetta's early .750 batting average and .857 on-base percentage might be a little hard to sustain, but his early approach has been a welcome sign for the 32-year-old after he dug himself a big hole for the Angels in 2015, hititng .091 with a .303 OPS in his first 22 games.
Iannetta learned from his struggles last season, when he eventually lost his starting job and finished the year with the worst line of his 11-year career at .188/.293/.335. He's adopted a finer focus this season, choosing to quit worrying about the overall numbers and zero in on the moment.
"I'm just trying to take it one at-bat at a time," he said. "That's something that I haven't done necessarily throughout the course of my career, just really focus on that one at-bat. I'm trying to really get my mind on that. I don't want to let it build on the positive side or let it build on the negative side. Just have a really short memory. It's going to be a lot harder in practice than it is just saying it, but we'll see what happens."
Manager Scott Servais appreciates that approach, knowing Iannetta is wired tightly and puts a lot of pressure on himself. Getting out of the gates quickly with his new team could help there, as well.
"Chris has been really good," Servais said. "I know he was very worried about it in Spring Training. He knows he's a slow starter; especially last year, he really struggled in April. He wanted everything to be perfect and feel good. He's really hard on himself, so it's really nice to see him get off to a good start."
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.