The veteran judge of the Fox talent competition declared Wednesday's final performance round at the Nokia Theatre a dead heat after finalists Kree Harrison and Candice Glover each performed three songs.
"Dude, this is so close," beamed Jackson, who announced last week that he's leaving the panel after his 12th season. "Everybody go vote!"
At the beginning of the night, Jackson declared Glover, the 23-year-old vocal powerhouse from St. Helena Island, S.C., the winner of the first round, which tasked the finalists with performing a song selected by "Idol" executive producer Simon Fuller.
Glover tackled Adele's "Chasing Pavements," while 22-year-old country crooner Kree Harrison of Woodville, Texas, took on Sarah McLaughlan's "Angel."
"I love you, Simon Fuller, but I would not have chosen those songs," Jackson said.
In the second round, Glover and Harrison admirably performed their potential future singles. Glover was assigned an empowerment ballad called "I Am Beautiful," and Harrison was appointed an emotional country tune titled "All Cried Out."
"These are both soul singers," noted judge Keith Urban, who gave the round to Harrison.
However, fellow judge Nicki Minaj said Glover edged out Harrison, who reprised Patty Griffin's "Up to The Mountain" as her final song. She previously sang it during the Las Vegas round.
For her third round selection, Glover infused Ben E. King's "I (Who Have Nothing)" with an a cappella opening. Both women earned standing ovations from the judges for their reprisals.
"Whatever happens is tomorrow, and tonight we're just trying to have fun and sing our best for y'all," Harrison said earlier in the evening.
The contestant with the most viewer votes will be revealed Thursday.