He scored his first senior international goal 10 days ago in the friendly win over Wales and earned his ninth cap in the thrashing of Latvia.
Both sides had chances after the break but it was Villa who looked the more threatening and they took the points when Buendia, who replaced Evann Guessand on the hour, curled a low shot into the far corner in front of the joyous visiting fans.
After a slow start to the campaign, Villa have now won five matches in a row and are up to 10th in the table with 12 points, while a second league loss of the season for Tottenham left them in sixth, behind Chelsea on goal difference.
It was a sobering afternoon for Tottenham, who would have gone second in the standings with a win, but after good starts to both halves they faded and lacked creativity.
_Reuters_