Former England forward Jay Rodriguez scored twice as relegated West Bromwich Albion got their first win of the season in a sensational 4-3 victory at Norwich City.
Former England worldwide Lampard won his first game as manager 2-1 against _ thanks to a last-minute victor, but couldn't repeat the trick in his first home game in charge.
Tom Lawrence equalised with a 12th minute free kick that Bailey Peacock-Farrell should have saved but Leeds responded by retaking the lead through Kemar Roofe's header from Ezgjan Alioski's cross in the 21st minute. Only a matter of minutes after Roofe's second of the afternoon, it all but ended Derby's chances and made sure of Leeds' 100% record thus far.
He said: "We were under no illusions as to how hard it would be beforehand but we didn't deal with what they threw at us". They outnumbered us in too many areas and that can't happen.
Derby will look to learn from mistakes against Leeds when they take on Oldham Athletic in the Carabao Cup on Tuesday night before resuming league play against Millwall on Saturday.
"I played the same way at Fulham and at Huddersfield; it was very much about high pressing and being on the front foot and that's what Frank wants as well".
No other team has defeated United more times than Derby since 2010, getting the better of their opponents 10 times.
Tom Lawrence's direct running was too much for Luke Ayling, the Leeds right-back bringing down the Welsh global outside on the edge of the penalty area. We didn't have control of midfield in the first-half, hence bringing Bradley Johnson on, and although we were initially better we can't just play good games in small bits.
But who did you think stole the show?