Richmond, 29, who two years ago was playing for Edmonton in an independent league, went 3-0 with a 2.70 ERA in four starts in April, and so far has continued his success with his first start of May, earning the win Sunday.
Richmond scored a victory in three consecutive starts from April 15-28 after a no-decision April 10 in his first start of the season.
Richmond struck out a season-high eight batters in his only home start of the month on April 23 against the Texas Rangers.
Jerry Garvin (1977), Chris Michalak (2001) and Gustavo Chacin ('05) are the only other Blue Jays rookie pitchers to begin April with a 3-0 record.
In his 10 career big league starts, Richmond has yet to allow more than three runs in a start.
"That's what I've been trying to do, keep our team in it and keep them under three runs," Richmond said on Tuesday after the Blue Jays defeated the Indians, 10-6, with a seven-run seventh. "Our offense is pretty impressive and I'm just trying to do my part.
"These guys are fighters -- we give up the four-spot [in the top of the seventh on Tuesday] and we come back with seven in the bottom of the inning. These guys are unbelievable. We young pitchers are trying to elevate our game, step up to the plate and do our job."
Larry Millson is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.