Koulibaly applied a smart finish to Marc Cucurella’s cross to open the scoring in his home debut following his move from Napoli this summer.
By scoring, he has become just the second Chelsea player to net his first league goal in a game against Tottenham.
“Kalidou Koulibaly is the first player to score his first Premier League goal for Chelsea in a game against Spurs since Michael Essien in March 2006,” reported Opta.
Essien scored his maiden topflight goal against the Blues’ North London rivals in 2006 and that record had stood for 16 years.
However, while Chelsea went on to win 2-1 against Spurs in that fixture, the Blues had to settle for a draw during Sunday’s clash.
Koulibaly’s goal had given Thomas Tuchel’s side a slender 1-0 lead following a dominant first-half performance.
Tottenham, though, came back strongly in the second half and restored parity through Pierre Emile Hojbjerg.
Chelsea appeared to have sealed all three points thanks to Reece James’ late goal but there was more drama as Harry Kane snatched a draw for Tottenham deep into injury time.