A statement from the European governing body said nothing untoward had been detected from Wednesday's Champions League Group D fixtures, including Real Madrid's 3-0 victory away to Dutch side Ajax Amsterdam.
Lyon, who had scored only twice in their previous five Champions League games, hit the net seven times in 30 minutes against 10-man Dinamo after going a goal behind, upsetting the odds to leapfrog Ajax and finish second in the group to reach the knockout rounds.
Croatian champions Dinamo said any suspicion was "shameful and malicious" and UEFA said nothing in Wednesday's results, or the betting patterns around the matches, merited an inquiry.
UEFA President Michel Platini said he had absolute faith in the integrity of the players.
"Personally, I have no doubt whatsoever about the integrity of the players in this competition," he told reporters after a meeting of the UEFA Executive Committee in Venice.
"When I was a player with Saint-Etienne, there was a game where we needed to score seven goals to have a chance of winning the title and we did it, but our rivals won their game 1-0 so it was for nothing."
UEFA, which uses a betting fraud detection system, said: "For the time being this system has not shown any irregular betting patterns around yesterday's games or their outcome that would justify any inquiry on that front."
UEFA said it had taken note of the widespread media coverage surrounding the games, adding: "UEFA considers the integrity of its own competitions, including the UEFA Champions League, as an absolute priority and pays extra attention to all games.
"We have also implemented a Betting Fraud Detections System (BFDS) as a tool against match-fixing - a system which monitors 29,000 games a season including all UEFA matches - and utilises data from more than 400 betting companies."
However, the statement added that UEFA could still act if the match officials felt something suspicious had happened.
"We are currently waiting to receive the reports of the referee, referee observer and match delegate to see if, in their opinion, something suspicious might have happened.
"If there is anything in these reports that could raise a doubt, UEFA may then charge a disciplinary inspector to investigate the matter. But there is nothing at this stage that would justify doing so."
GOAL DIFFERENCE
The French online betting authority (ARJEL) also issued a statement saying it had not detected anything untoward.
"No irregularity has been detected concerning the total amount of stakes or the number of bets," it said.
Before Wednesday's matches, Real had already qualified for the last 16 with 15 points from their first five games, Ajax were second with eight points and a plus-two goal difference and Lyon third on five points with a minus-four goal difference.
As both games between Lyon and Ajax had ended 0-0, that meant, if Lyon won and Ajax lost, the two would both finish on eight points and overall goal difference would be the first criterion to determine who would qualify in second place.
Lyon needed a huge goal swing of seven to oust Ajax from second place, which is what happened. Their 7-1 win meant they finished with a goal difference of plus-two, while Ajax's plus-three difference was wiped out by their 3-0 loss to Real.
Dinamo reacted angrily to suggestions that the game could have been fixed.
"It is tendentious, shameful and malicious to have doubts about the regularity of the game in Zagreb and thus belittle Lyon's success," the Croatian champions said in a statement.
"It was a shameful result for Dinamo and we hav
