Shemonia finished 4 for 4 in his events at the meet.
He captured the district title in the 1,600 by more than 7 seconds. He crossed the line in 4 minutes, 37.5 seconds.
Shemonia, who already signed to run at SIU Carbondale next year, won the 800 by 4 seconds. He finished in 1:59.79 to edge teammate Eric Essner.
His perfect day in individual events finished with a win in the 3,200. He finished in 10:25.12.
Shemonia also was part of the Rams' victorious 3,200 relay team. Scott City finished in 8:34.89, which was more than 27 seconds better than second-place Herculaneum.
Shemonia, the reigning Class 2 cross country state champion, will compete in Saturday's Class 2 Sectional 1 in an attempt to qualify for the Class 2 state meet.