In celebration of the Navy and the Marine Corps both turning 250 years old, a packed agenda of events are taking place in Philadelphia. One of the more recent ones: a cheesesteak competition between the Navy and Marine Corps.

While on board the USS Arlington, South Philly cheesesteak legend Tony Luke Jr. started by giving the group of competitors a demo on how to make the perfect cheesesteak.

Luke is behind the famous cheesesteak franchise Tony Luke's, which started in South Philadelphia in the '90s.

"The first thing you want to do is put some oil on the grill," Luke said. "There isn't just cheese on the top, cheese is throughout the whole sandwich."

After Luke gave a quick tutorial, it was up to each chef to craft the perfect cheesesteak.

One by one, six cooks left it all on the grill until it was time for the taste test.

The judges were Rear Admiral Stephen D. Barnett with the United States Navy and Commanding Officer of the USS Arlington, Captain Ian J. Scaliatine.

The two inspected each sandwich, took notes and left behind a graveyard of cheesesteaks. 

Finally, a winner was announced — Yessica Canales Rivas of the Marine Corps took home the gold. 

"It was shocking to be honest," Rivas said. "I didn't think I was going to be the one winning."

She's a 3531 Motor T Operator for the Marine Corps, but she isn't new to the kitchen.

"Before I joined the Marine Corps though, I used to work in a hoagie place," Canales Rivas said. "So, I kind of have some background in actually making hoagies, but I never thought I'd be making hoagies in the Marine Corps."