Tonnessen made 21 saves as RIT won its second consecutive Empire 8 Men’s Lacrosse Championship title. He stopped nine shots and allowed just three second-half goals in the Tigers’ 13-9 come-from-behind win over Ithaca in the semifinals. Tonnessen followed that up with 12 saves and allowed just seven goals in the Tigers’ 24-10 title game victory over Nazareth. He also scored his first collegiate goal and set the program’s single-season record for wins with 17.