Chelsea recorded the highest net-profit of any club in world football in the last two transfer windows, according to newly published data.
Serving a transfer ban last summer after being deemed to have breached FIFA regulations on the recruitment of young players, Chelsea spent just €45m (around £38m) to turn Mateo Kovacic's loan from Real Madrid into a permanent deal.
The west Londoners made a further €205m (£173.7m) in player sales, stemming largely from the €100m plus add-ons sale of Eden Hazard to Real Madrid.
By contrast, Real Madrid posted €181m in negative balance on transfers, according to research by the CIES Football Observatory.
Aston Villa were also low down on the list, second only to Real, spending €172m on players following their promotion from the Championship and earning just €3m in return for an €169m balance.
Overall Premier League clubs fared poorly, having the largest net deficit of any of Europe's top five leagues and accounting for a combined €844m (£715m) more in outgoings than money they earned.
Chelsea, who posted losses of £96.7m in the latest financial results , are the only Premier League side to feature in the top 10 of clubs in terms of net earners.
Benfica, who earned €113m from the sale of Joao Felix to Atletico Madrid in summer 2019 window, came second with a €166m net profit, with Ajax in third with €137m - aided by the departures of Matthias De Ligt to Juventus and Frenkie De Jong to Barcelona.
Manchester United, meanwhile, placed fourth and Tottenham fifth, with spends of €151m and €141m more than they earned respectively. Arsenal came 11th spending €85m more than they earned in player sales.