St. Clair High School student Sean Lawrence holds the check above his head in shock during a school assembly Friday morning, May 8, 2015. (Tanya Moutzalias | MLive Detroit)

St. Clair, MI- St. Clair High School senior Sean Lawrence knew he had won a $20,000 scholarship from H&R Block for his financial skills in the H&R Block Budget Challenge, but what he didn't know is that he placed first and would win the grand prize scholarship of $120,000.

During the school's end of the year assembly Friday morning, Lawrence and his classmate Matt Kerrigan were both awarded $20,000 checks from H&R Block's President and CEO Bill Cobb.

Lawrence thought he was receiving just one of the 133 $20,000 scholarships awarded, until he was brought back up on the stage.

His $20,000 check was replaced with a $120,000 check. To the cheers of his classmates, Lawrence was in awe that he had won the top H&R Block scholarship prize in the country.

Lawrence placed first in the H&R Block Budget Challenge out of 93,000 high school students across the country.

"Never in our wildest dreams did, we thought that he would he get something like this for all his hard work, studies and dedication. Words can't even express how proud we are and how smart he is," said his mother Diane Lawrence.

"It changed his life somewhat, definitely," said his father Steve Lawrence. "Life changing," added his mother.

Lawrence had planned to start at a community college for two years while pursuing a degree in chemical engineering, now he may be able to jump head first into a four-year university.

Kerrigan also plans on studying chemical engineering and has chosen to attend Central Michigan University.

The H&R Block Budget Challenge is a "teacher-tested, online simulation tool that replicates real-world budgeting and personal finance decision making. By simulating an adult's financial life- paying bills, investing in retirement, managing loans and more- student take a persona finance 'road test.'"

H&R Block also donated 25 brand new laptops to St. Clair High School.

Two other students in Michigan were awarded $20,000 scholarships, Kristy Godley and John Lambrecht at Ithaca Junior Senior High School in Ithaca, MI.