With Mike Napoli on the disabled list and Mike Carp dealing with a fractured right foot, Farrell felt the occasion was right for the move.
"The way Brock has solidified the leadoff spot and handled the bat, we're finding ways to keep him on the field and keep his bat in the lineup," said Farrell. "We don't feel it's risky at all. He's a good athlete, he's a good infielder. Granted, there's been no experience at the position, but given where we are, we're not hesitant to put him there."
Holt cleanly picked Kevin Kiermaier's grounder in the third and made a clean throw to Jon Lester at the bag to record the frame's first out. Holt was charged with an error in the eighth when he dropped a throw from Xander Bogaerts.
Holt spent time before the game working with infield instructor/third-base coach Brian Butterfield.
"It's more about just getting some reps prior to fielding a throw across the diamond," said Farrell. "And that's getting his bearings on where the bag is going to be as he's making his way over there to anchor himself so, yeah, a little bit of a crash course. He's a good athlete and a good player. Like I said, given where we are, that's the option today."
Holt saw his average jump from .305 to .337 as he notched four doubles and drove home two runs.
"I'm just trying to stick with my approach, getting ready to hit and putting a good swing on it," said Holt. "I'm seeing the ball well right now. Just going up there with some confidence, and like I said, put a good swing on the ball."
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.