Gary Anderson and Gary Robson have been cleared of wrong-doing after irregular betting patterns preceded their Lakeside World Championship match.
Bookmakers said Anderson, who won the first-round tie 3-1, had been backed to the near exclusion of Robson, costing the industry a possible six-figure sum.
The Association of British Bookmakers (ABB) will not launch an inquiry.
And both players have been cleared by the British Darts Organisation (BDO) after interviews uncovered nothing.
ABB spokesman John Johnson said: "I understand the BDO has interviewed both players and given the situation a clean bill of health, so there's not really anything more we can do."
Bookmaker William Hill was forced to suspend its market on the match within two hours of opening it last Thursday, having been inundated with support for Anderson.
"We saw some of the strangest ever betting patterns on an early-round darts match in a major competition," said William Hill spokesman Graham Sharpe.
"We thought it was a flip-of-a-coin type of match and opened up with both players at 5-6. We were knocked over by people wanting to back Gary Anderson.
"In normal circumstances you would maybe take a couple of thousand pounds. But in this case it was well into five figures within two hours, and the interest was only in one of the two players.
"We therefore took the almost unprecedented step of closing the book, but we will stand by those bets and pay up."
Coral spokesman Simon Clare added: "Nobody wanted to back Gary Robson - we hardly took a bet on him.
"We are paying out through gritted teeth but we have serious concerns about the betting patterns and would welcome an inquiry."
But the BDO and the International Darts Players' Association (IDPA) were united in insisting nothing untoward had occurred.
IDPA chief executive Martin Fitzmaurice said: "We have spoken to both players today. They categorically deny any involvement in the betting activity, and we would know if they were lying."
BDO managing director Olly Croft added: "The players were told about the betting activity and were distraught. They are the most honest people in the world."