The reigning UK Open champion kept the heat on the top four with wins against Andy Hamilton and Adrian Lewis.
The Scottish star saw off Hamilton 7-4 before ending a brilliant night with a 7-5 triumph over Lewis.
“That was two very important wins for me,” admitted Thornton, who had lost his previous two matches.
“I have been quite scrappy in the last two weeks and I got a lot of second chances tonight but I took them.
“I’m still in there fighting and a lot of people would not have predicted that.
“I’m looking forward to the challenge in the next couple of weeks.”
Thornton missed a string of darts to win the opening leg, allowing Hamilton to break, but the Scotsman pegged double top to return the favour before holding on double ten to move ahead.
‘The Thorn’ missed a dart at the same bed for a 100 checkout to break again but he did so anyway, returning to pin double ten at the second attempt.
Thornton pegged double two to move 4-1 ahead before ‘The Hammer’ pulled a leg back.
Thornton responded with a 180, followed by a 41 finish to restore a three leg cushion before nailing tops again for another break of throw.
Hamilton set about fighting back for a draw by breaking Thornton’s throw before holding to reduce his opponent’s lead to 6-4.
But a 180 in the eleventh leg helped the Ayshire ace to seal the victory as he finished 83 on the bull to complete a double over ‘The Hammer’.
Thornton grabbed an early break of throw against Lewis before hitting double top to double his lead.
‘Jackpot’ pulled a leg back but Thornton pegged tops again to make it 3-1.
‘The Thorn’ fired in a 180 but it wasn’t enough to grab another break of throw as Lewis reduced his lead.
The double World Champion levelled up proceedings before pinning double twelve to edged in front for the first time.
Thornton produced a brilliant 120 checkout to level at four legs apiece before regaining the lead with a break of throw.
He then produced a spectacular finish of 152 to make sure of at least a point.
Lewis pegged double ten to set up a decisive leg, which Thornton won in style with a magnificent 145 finish.
Thornton takes on Phil Taylor next week.
By Chris Murphy
Image courtesy of Lawrence Lustig/PDC