MASON CITY — The Marshalltown baseball team scored the first and last runs of the night.

Mason City scored 36 in between.

The Riverhawks rattled off their 24th-straight wins in the series with victories of 20-1 and 16-1 in Thursday’s Iowa Alliance Conference North Division doubleheader at Roosevelt Field.

Both games were shortened to four innings by the mercy rule as Mason City (14-6, 6-2) secured its 11th straight doubleheader sweep over the Bobcats.

Marshalltown (4-13, 1-7) took a brief lead in the opening game when Garrett Thede reached with a one-out walk and scored on Jalen Logsdon’s double over the right-fielder’s head.

That was just about all the offense the Bobcats mustered on this night. Senior left-hander Eli Schultz allowed only one other hit — a third-inning single by Thede — and got plenty of run support. Schultz struck out seven and walked three in the four-inning win and had the first of Mason City’s 12 hits in the opener.

Gabe Ries hit a two-run home run, Bennett Miller had a pair of three-run homers, and the Riverhawks totaled six extra-base hits. Four Marshalltown pitchers combined to walk 11 batters and the defense made three errors in the loss.

“We gave up too many extra outs and bases to Mason City and they took advantage of them,” said MHS head coach Colton Hanke. “We need to clean things up heading into Ottumwa to close off the week.”

In the nightcap, Mason City scored nine times in the opening frame and led 16-0 before the Bobcats got on the board in the top of the fourth. Logsdon singled and scored after back-to-back walks to Madden Martin and Quinn McLeod and a sacrifice fly off the bat of Larrs Schoenfelder.

Logsdon had both of Marshalltown’s hits in the second game and three of four for the night.

Martin and Dane Hoogensen combined to allow 11 hits — six for extra bases — from the mound for MHS, while the defense made seven errors.

Schultz was 2-for-3 with a double and four RBIs and Ries hit two triples for the Riverhawks, who have won nine in a row.

The Bobcats hit the road for Ottumwa on Friday night to make up Wednesday’s washed-out doubleheader in cross-Alliance play. Marshalltown hosts Des Moines North for a twinbill on Monday.