Pope Francis implored sports leaders on Wednesday to do a better job of keeping corruption off the playing field.
Speaking at the first global conference on faith and sport, Francis said sports must be protected from manipulations and commercial abuse.
"It would be sad for sport and for humanity if people were unable to trust in the truth of sporting results, or if cynicism and disenchantment were to drown out enthusiasm or joyful and disinterested participation," Francis said.
The pope's challenge comes during a period of widespread corruption in sports, from various scandals at FIFA to Olympic ticket abuses to match-fixing in numerous leagues and games.
Members of the International Olympic Committee, soccer executives and athletes were attending the three-day conference in the Vatican.
"In sport, as in life, competing for the result is important, but playing well and fairly is even more important," Francis said. "I trust that these days of meeting and reflection will allow you to explore further the good that sport and faith can bring to our societies."
Francis has denounced doping in sport, saying drug-fueled victories are "sterile." He has urged athletes to be clean and to use sport for personal development and solidarity.
Francis has also spoken out strongly about corruption in all aspects of society and urged young people to resist its addictive lure.
U.N. Secretary General Ban Ki-moon and IOC President Thomas Bach were special guests for the opening ceremony of the convention, called Sport at the Service of Humanity.
"It was very inspiring," Bach told The Associated Press of the pope's speech. "That's what we all have in common. We are joining forces in the fight against corruption, for instance."
"We know that he's a great friend of sports and he's appreciating the values of sport very much," Bach added. "We could feel that in this speech today and also in the private audience."
Former Juventus great and Italy World Cup winner Alessandro Del Piero took part in a ceremonial kickoff for the event with a soccer ball on stage.
"Sport is passion for me," Del Piero said. "I always tried to give my all in full respect of the rules and with the great passion that always made me stand out, together with desire and humility, in pursuit of my dreams."