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.
Clarke turned on the style again after the restart, looping in a cross that Scott Carson could only parry to the waiting Alioski, who teed up Jack Harrison for a simple finish.
Referee Davies failed to spot a foul in the box by Tom Lawrence soon after, although Bailey Peacock-Farrell was fortunate to escape punishment for a high lunge on Duane Holmes at the other end.
Leeds' victory takes them five points clear of nearest challengers Norwich City, who face fourth-place West Brom on Saturday, while Derby remain in sixth.