Every start is a learning experience for Nick Tepesch, and he learned another valuable lesson Friday against the Blue Jays.

“You can’t hit the nine-hole hitter with a curveball,” Tepesch said. “You can’t do that. Stuff like that sets the tone.”

In a wrong way.

A good start unraveled for Tepesch quickly after he hit the Jays’ nine-hole batter to start the sixth inning. Toronto scored four runs that inning and went on to a 6-1 victory over Texas in a crisp, 2-hour, 8-minute game.

The Rangers remain in an offensive funk and have lost seven of their last 11. They fell to second place in the American League West standings for the first time since April 20. The A’s hold a half-game lead after defeating the White Sox on Friday.

It got off to a promising start for Tepesch and the Rangers. He retired the first nine batters before giving up a leadoff homer to Melky Cabrera in the fourth inning that tied the game at 1-1.

Tepesch then worked a perfect fifth before running into the troubling sixth. He yanked an 0-1 curveball inside that hit the Jays’ No. 9 batter, Munenori Kawasaki.

Cabrera followed with a single to right on the first pitch he saw, Jose Bautista drew a four-pitch walk to load the bases, and Edwin Encarnacion delivered a blow with a two-run double to left-center field on a sinker that was down and away.

Adam Lind and J.P. Arencibia brought in two more runs for a 5-1 lead on sacrifice flies that were also hit on the first pitch of those at-bats.

“They just came out ambushing the first pitch,” said Tepesch, who threw only 11 pitches in the four-run sixth.

“They did a great job of situational hitting, what do you do?” catcher A.J. Pierzynski said. “It just happened so fast. He threw great except for a five-pitch span there.”

Asked what Tepesch could take away from his outing, Pierzynski said: “If he pitches like he did tonight, he’s going to win a lot of games.”

Tepesch gave up another run on an RBI single by Cabrera in the seventh.

It was the deepest Tepesch has pitched since his big-league debut on April 9, but the six earned runs were the most he’s allowed. In fact, Tepesch allowed six runs total in his four April starts.