Spurs fell out of the Premier League top four on Saturday, have now won only two of their past seven matches.
Villa have won back-to-back away league games as they improve under Unai Emery.
A poor match for Spurs’ World Cup-winning defender Cristian Romero, who was shown a yellow card in the first half – and fortunate not to get a second late on after barging Philippe Coutinho – while Lloris endured a shocking moment in the 50th minute.
He spilled Luiz’s long-range effort and Ollie Watkins squared the rebound for Buendia to slam home.
Luiz started and finished the move for 2-0, sliding a pass to John McGinn before racing on to receive the return and chipping cutely past Lloris.
Spurs were booed off at the final whistle, while some fans directed angry chants directed towards chairman Daniel Levy.
An error by goalkeeper Hugo Lloris in his first game back since the World Cup allowed Emiliano Buendia to score before Douglas Luiz doubled the lead.
However, Spurs set an unwanted club record of conceding at least two goals in seven successive Premier League fixtures.
They looked toothless in attack – Bryan Gil made his first league start in place of the injured Dejan Kulusevski, but was replaced just past the hour following an anonymous display – and Conte looked more miserable as his side slipped towards another worrying defeat.
Emery maintains strong Spurs record
While Emery’s reign at Arsenal was not a success, he did manage to get the better of Tottenham – going unbeaten in three games against their local rivals.
He continued that trend on Sunday, a solid defensive performance justifying the decision to leave a World Cup winner on the bench.
Martinez’s heroics in Qatar were not enough to unseat Olsen as Emery named an unchanged team from the side that lost to Liverpool on 26 December.
He was rewarded. Watkins and Buendia were bright to pounce on the opening Lloris handed them, while Luiz controlled midfield and deserved his goal.
They ensured Emery became the first Villa manager since John Gregory in 1998 to win his first two Premier League away matches.
The Spaniard also set a record of 55 Premier League games in charge without being involved in a goalless draw, surpassing former Spurs boss Ossie Ardiles.
