Right-hander Ben Melius gave a clinic on how to work a lineup Tuesday, tossing a six-hitter for Winthrop in a 3-1 amateur baseball victory over the Kato Cubs at Franklin Rogers Park.

Melius, the ace of Winthrop’s staff, used an array of offspeed pitches to keep the Cubs lineup off balance for most of the night. He finished with five strikeouts, walked four and gave up one earned run.

“It was mostly curveballs and sliders,” Melius said afterward. “My fastball was popping a little more than usual so I was able to use that in some key spots, too.”

Winthrop jumped to a 1-0 lead in the top of the first. Scott Palmer drew a one-out walk off starter Brendon Watts, went to third on a single down the left-field line by Ben Melius and scored on a grounder to short by Chris Fahey.

The visitors added two more runs — both unearned — in the top of the second. With two outs, Jared Werner reached first when his swinging third strike rolled to the backstop for a passed ball. Two hits and two wild-pitches later, Winthrop had a 3-0 lead.

The Cubs scored their only run in the bottom of the third. Chris Ward walked, advanced to second on a wild pitch, moved to third on a ground out and scored on a single to right by J.J. Cattrysse.

Mankato had a golden opportunity to score again in the seventh but took themselves out of a rally with some over-aggressive base running.

With runners on first and second and one out, Tyler Kuch bounced a single up the middle. Center fielder Pat O’Malley picked the ball up cleanly and threw a strike to home where catcher Andy Melius easily put the tag on Jon Howard trying to score from second.

“I made a poor decision to send him,” said Cubs manager Art Westphal, who waved Howard home from the third-base coaching box. “When you consider the situation, with J.J. Cattrysse coming up, it would have been smarter to hold him up.

“We got a few hits tonight but we didn’t get the key hits. We didn’t get the hits with runners in scoring position. You have to give their pitcher credit for a lot of that, he pitched a nice game.”

Kuch was the only Mankato player with two hits and Cattrysse had the only RBI. O’Malley and Kris Swenson had two hits apiece for Winthrop (8-13).

The Cubs (8-8) are off until Sunday, July 12, when they take on the Cleveland Spiders at Wolverton Field. Starting time is 2 p.m.