TORONTO — On Opening Day, every Yankees employee would have been elated if told that in the second week of August, their club would be running away with the AL East.

Would any reasonable mind, however, have believed Gio Urshela and Mike Tauchman would be driving the train?

Urshela started the season at Triple-A and Tauchman played sparingly and not well with the varsity in April and half of May before being sent to Scranton/Wilkes-Barre.

Urshela replaced an injured Miguel Andujar at third and Tauchman returned in the middle of June. And lately the duo has been a major reason the Yankees have the best record in the AL.

“They have been impact players for us and do it on both sides of the ball,’’ Aaron Boone said of his accidental stars. “It has come in a lot of big situations. I don’t know how many more ways we can describe it.’’

Thursday night’s 12-6 beating of the Blue Jays in front of 34,108 at Rogers Centre was fueled by Urshela’s 3-for-5, two-homer, four-RBI evening and Tauchman’s 2-for-5, one-homer, four-RBI performance.

The victory extended the Yankees’ longest winning streak of the season to nine and improved their AL East lead over the idle Rays to 10 ½ lengths.

“I think on offense we are kind of in a zone lately. Look at the production we are putting up,’’ said Tauchman, who hit a two-run homer in the third inning, when the Yankees scored six runs.

The Yankees have slugged 19 homers in four games — a major league record — so people in the seats might want to think about donning hard hats while sitting in that danger zone.

And that is with Giancarlo Stanton, Aaron Hicks, Gary Sanchez, Luke Voit and Edwin Encarnacion on the injured list. Not one of those 19 homers was hit by Aaron Judge.

“Trying to hit the ball in the zone and hit with power,’’ said Urshela who also homered twice Wednesday night in Baltimore and is the seventh player in Yankees history to hit five homers in three games. The most recent had been Alex Rodriguez in 2007.

The hitting clinic appeared to have delivered enough runs after three innings, when the Yankees held an 8-0 lead. But Domingo German (15-2) gave up four runs in the fifth, when he almost didn’t survive the inning, but got through it and qualified for the victory.

“I think his stuff overall was a little down,’’ Boone said of German, who tied Astros right-hander Justin Verlander for the major league lead in victories despite allowing four runs (three earned) and eight hits. “A little flat.’’

DJ LeMahieu (3-for-5) drove in two runs in the sixth for a 10-4 lead and after the Blue Jays had scored a run against Chad Green. Luis Cessa gave up one run in the final three innings to post his first save of season. To make sure the Blue Jays didn’t come back, Tauchman delivered a two-run, two-out single in the ninth.

Tauchman was imported from the Rockies in the final hours of spring training to provide cover for the outfield when Hicks started the season on the injured list. Urshela’s reputation with the Indians and Blue Jays was as an exceptional fielding third baseman who couldn’t hit enough to hold a steady job at a position that requires a productive bat.

Now, both are major forces as the Yankees have made a joke out of the AL East.

Anybody who says they saw that coming is a liar.