In rehearsals, Adam was hit by confidence issues.
"The first thing you have to do is believe in yourself," Sir Tom advised, "Else you won't get through to the people."
The pair performed Kings of Leon classic Use Somebody together for coach Sir Tom.
Deciding between the pair, he said: "Strong vocalists – you both did a great job, and now comes the difficult part for me.
"I think the person that I’m going to take through to the live rounds is Adam."
Watch Adam Isaac and Denise Morgan battle below...