Cole Hamels doesn’t remember the last grand slam he gave up, and there’s a pretty good reason for that.

It wasn’t in the majors.

It wasn’t in the minors.

Maybe it was at Rancho Bernardo High School in California, from which he graduated in 2002.

Hamels has no idea.

So Billy Butler’s fifth-inning blast Sunday afternoon was the first grand slam Hamels has allowed in at least 11 years. The drive just over the left-field fence led the Royals to a 9-8 win over the Phillies at Citizens Bank Park (see Instant Replay) and was the big blow in one of the worst outings of Hamels’ eight-year major-league career.

“It’s unfortunate, because a grand slam [almost] definitely puts your team behind, no matter how many runs you have,” Hamels said. “Four runs is a definite momentum changer. That’s obviously what it did today.”

The three-time All-Star was hit hard for a second straight start, allowing a career-high eight earned runs in 5 2/3 innings as his ERA ballooned to an ungainly 10.97 two games into the season.

For the first time since April 2009, Hamels has had consecutive starts allowing five or more earned runs in six or fewer innings. Last year he had no such starts all year.

The Phillies staked Hamels a 4-0 lead after one inning, but he allowed two runs in the third, the grand slam in the fifth and then, after Charlie Manuel finally ambled out to the mound to yank him in the sixth, Chad Durbin allowed the two baserunners he inherited to score for another two runs.