Real Madrid has topped the table of the world's 20 richest football clubs, displacing Manchester United with record revenues of €750.9m (£674.6m).
Man Utd slipped to third with Barcelona making it the first Spanish one-two since 2014-15, said Deloitte.
Its Football Money League, based on season 2017-18, also shows the combined revenues of the top 20 clubs has risen 6% to €8.3bn (£7.4bn), a new record.
There were a record six English Premier League clubs in the top 10.
The list, the 22nd of its kind, only looks at revenues and does not take into account club debts.
This gap this year between the top two places was the second widest yet, with €60.5m between the leading pair.
Real Madrid won their third successive Champions League, beating Liverpool 3-1 in Kiev last May.
That helped raise income for Los Blancos, who have now topped Deloitte's money league 12 times.
The club experienced commercial growth of €54.8m, including an increase in sponsorship and merchandising revenues, as well as exploitation of increasingly lucrative pre-season tour matches.
At €356.2m, Real Madrid now have the highest commercial revenue of any football club globally, contributing to those world-record revenues.
Dan Jones, head of Deloitte's sports business group, said: "Real Madrid's outstanding financial performance in 2017-18 is built on their long history of success on the pitch, most recently three consecutive Champions League titles.
"This has enabled the club to continue to drive commercial revenue as the appetite to partner with Europe's most successful clubs remains stronger than ever."
He said most of Deloitte's top 10 of our top 10 were through to the round of 16 in this season's Champions League and forecasting further revenue growth.
Bayern Munich and Manchester City completed the top five, retaining their positions from the past two years.
Paris St-Germain, Liverpool, Chelsea, Arsenal, and Tottenham Hotspur occupied places six to 10, with Spurs making it into the top tier for only the second time, having last appeared in 2006-07.
Everton were in 17th spot, Newcastle United 19th, and West Ham United 20th.
All the 20 clubs represented are from the "big five" European leagues, with Italy having four places, Germany and Spain contributing three clubs, and France one.
Other findings include:
- Spurs have capitalised on playing a full season at Wembley Stadium which has seen match-day revenue increase by 54%
- Paris Saint-Germain have reversed two consecutive years of decline
- AS Roma and AC Milan return to the top 20 thanks to performances in Uefa competition
- Turkish giants Besiktas have achieved their highest ever ranking, at 26th
"The substantial presence of Premier League clubs continues to be felt in this year's Deloitte Football Money League," said Deloitte's Sam Boor.
"However, with the Premier League's tender for the next cycle of domestic rights from 2019-20 complete and sale of overseas rights nearing conclusion, it is clear that Premier League clubs will be unable to rely on explosive growth in broadcast distributions as a source of future growth, as has been the case in recent years,
"As a result, we expect an even greater emphasis among these clubs on generating their own growth in the coming season, and in particular the optimisation of commercial revenue, which has been a key area for differentiating growth across most of Europe's leading clubs in recent years."