Leeds went ahead through Patrick Bamford but Betis scored the game's next three goals and United were unable to peg the Spaniards back despite a cool finish from Mateusz Klich just before the hour mark.
Real Betis finished sixth in La Liga last season and are heading for the Europa League.
Yorkshire Evening Post football writer Lee Sobot hands out the marks from Saturday afternoon's friendly in Loughborough.
Pictures by Bruce Rollinson.
Yorkshire Evening Post football writer Lee Sobot hands out the marks from Saturday afternoon's friendly in Loughborough.
13. Mateusz Klich (sub)
7 - Another player to impress after coming off the bench in replacing Firpo at half-time as Dallas went to left back. Clearly trying to get forward as much as possible and produced an ice-cool finish to net United's second goal.
14. Tyler Roberts (sub)
5 - Struggled to get involved after being handed a chance in the no 9 role. Had the game's last chance when cutting inside and shooting from the edge of the box but his effort went well wide.
15. Helder Costa (sub)
5 - Replaced Harrison on the left wing and saw a fair amount of the ball but could not produce the end product. Strayed offside when potentially in from a reverse pass from Koch.
16. Sam Greenwood (sub)
N/A - Only came on in the closing stages when Struijk went off injured but the 19-year-old forward is clearly very prominent in Marcelo Bielsa's thoughts when it comes to the first team.