FIFA President Sepp Blatter said Saturday that goal-line technology "works" and that referees were happy to see it implemented, as a trial of rival systems at the Club World Cup in Japan enters its final stages.
The world body has been testing two technologies that determine whether a ball has crossed the goal-line -- the camera-based Hawk-Eye and the German-developed Goalref, which utilises magnetic fields and a ball fitted with a microchip.
Although the intercontinental competition has yet to witness a contentious goal-line decision for the rival systems to judge, Blatter said the early signs were good.
"For the time being we can only say 'it works'," Blatter told a news conference in Tokyo, a day after FIFA held its final Executive Committee meeting of the year.
"We have had no critical situations so far and we will make an assessment after the final matches tomorrow.
"But the one thing I can say is that the referees are happy to have this help for them because they know now that if there's a conflicting situation it is possible to get the assurance to say if it was or wasn't a goal."
FIFA granted licences to Hawk-Eye and GoalRef following a lengthy testing process lasting around two years.
They were galvanised into action by England midfielder Frank Lampard's long-range shot against Germany in the 2010 World Cup which was clearly over the line but was missed by officials.
"At that time I was president of FIFA and I said if I'm still the president of FIFA at the World Cup in 2014 then we cannot afford to have the same situation. if an accurate system exists," Blatter said of the "ghost goal" in South Africa.
"There are two systems (now) and they are accurate. So far we are very confident, referees are confident and players are confident (of both systems)."
GoalRef will be tested in the Club World Cup's final two matches at Yokohama's International Stadium on Sunday -- the third place play off and the final between Corinthians and Chelsea, in which Lampard is expected to feature.
Hawk-Eye's trial ended on Wednesday when Al Ahly lost to Corinthians at Toyota stadium.
One of the systems is likely to be chosen for June's Confederations Cup in Brazil and the World Cup in 2014, following an analysis of their performances during the Japan showpiece.