According to Oddschecker, which compiles the odds offered by a selection of games companies, Carl Espen, who had been hovering in third place among the competition's participants with his song Silent Spring, dropped to eighth place after the semi-final on Tuesday showed the strength of competition.
"Sanna really carried off one of her best performances last night," Torbjorn Ek, a Eurovision specialist for Sweden's Aftonbladet newspaper, told VG.
He said that he expected Carl Espen to make it to the finals when he sings on Thursday.
"If he delivers and feels confident on stage on Thursday -- not afraid as he has been in the past - I think Norway can be confident of going to the final," he added.
Once it gets to the final, he argued that Carl Espen's decision to sing a slow, plaintive ballad made it crucial at what point he takes to the stage.
"The kind of song that Carl Espen is singing makes it important to sing late so that people remember the song properly," he said.