Leeds midfielder Anton Stach's World Cup hopes are in jeopardy after the German was stretchered off in the 1-0 victory against Brighton.
Dominic Calvert-Lewin scored Leeds' winner in stoppage-time at Elland Road to damage seventh-placed Brighton's hopes of European qualification.
Brentford, in eighth place, also suffered a blow to their European ambitions in a 2-2 draw against Crystal Palace.
Ismaila Sarr's sixth-minute penalty put Palace ahead before Dango Ouattara hauled Brentford level in the 40th minute.
Adam Wharton restored Palace's advantage with his first goal for the club in the 52nd minute, but Ouattara struck again in the 88th minute.
Sunderland are in contention for European qualification after a 3-1 win at Everton that dented the hosts' own ambitions of making it into continental competition.
Merlin Rohl cast a spell on the Sunderland defence with his deflected 43rd-minute opener.
But Brian Brobbey equalised in the 59th minute and Enzo Le Fee put ninth-placed Sunderland ahead in the 81st minute before Wilson Isidor wrapped up the points in stoppage-time.
Fulham's dreams of Europe were hampered by a 1-1 draw at relegated Wolves.
Wolves took the lead through Mateus Mane's 25th-minute blast, with Antonee Robinson equalising with a penalty in first-half stoppage-time.
