Leeds United put pre-match controversy to one side to defeat Derby County 2-0 and move five points clear at the top of the Championship.
Marcelo Bielsa took responsibility for the Leeds spy scandal, after Derby had accused their opponents of sending a staff member to view the Rams' training session on Thursday, with the incident set to be investigated by the Football Association.
But the admission from the Leeds boss had little impact on his side's fine performance as Leeds bounced back from a three-match losing streak in all competitions.
Andre Wisdom's clumsy foul on Ezgjan Alioski 32 seconds in saw referee Andy Davies award Leeds a penalty, but a surprising offside flag came to Derby's rescue.
Frank Lampard's side could not match their hosts' intensity, however, and were behind when Jack Clarke marked his first Championship start with a sublime assist for Kemar Roofe to hammer home from close range.