YONKERS, N.Y. — It’s not easy to defend a national championship in any sport, especially in soccer.

And that just might go double when a game involves two top-flight teams from one of the best, if not the leading adult league in the United States.

Case in point:

In a battle of Cosmopolitan Soccer League teams, the New York Greek Americans upended defending national champion Lansdowne Bhoys in the U.S. Amateur Cup at Tibbets Field Tuesday night.

The Greeks outlasted Lansdowne in a shootout, 7-6, after playing to a scoreless draw in the U.S. Adult Soccer Association competition.

Needless to say, the winners were ecstatic.

“Great performance from the boys tonight,” Greeks player Tyler Botte said on Twitter. “Nothing new from this bunch and tactical wizard Ricardo Zidane Nuttoli!”

Botte was referring to Greek Americans coach Richard Nuttall.

“What a performance from the lads tonight!” midfielder Shaun Foster tweeted. “To knock out the current national champions in the 1st round doesn’t get any better.”

Lansdowne wished its CSL rivals luck.

“Bhoys are out,” the club said on Twitter. “Good luck to Greek American.”

Over the summer, Lansdowne pulled off the double, capturing the Werner Fricker Cup and U.S. Amateur Cup over a period of a few weeks.