Leeds produced a scintillating display to brush aside Derby but the 2-0 win was overshadowed by Marcelo Bielsa's admission that he was behind the spying incident at the Rams' training ground.
The build-up to the Sky Bet Championship fixture was dominated by Derby's claim that a Leeds employee was escorted from the perimeter of their training complex by police on Thursday after "acting suspiciously".
Bielsa accepted responsibility for the incident in a pre-match interview, although he insisted he had done nothing illegal as home fans chanted "All spies aren't we" and "We're Leeds United, we'll spy where we want".
The United head coach could face action from the Football Association but he would have been delighted with his side's response on the field as they beat Derby comfortably for the second time this season.
Kemar Roofe scored his 14th goal of the campaign to give Leeds a deserved half-time lead and the hosts secured three welcome points just after the restart thanks to Jack Harrison's tap-in.
The result ended Leeds' three-match losing run and stretched their lead at the top to five points, denting Derby's hopes of catching the top two in the process.