Leclerc started Sunday's race on pole-position for the first time in his career, but a bad start for the Monegasque driver and an excellent start from Vettel ensured the German driver was in the lead for a brief period of the Bahrain GP.
Leclerc used the DRS zones on the track to catch up with his team-mate before making the move and started to lead his first ever grand prix.
"It's always a tricky situation when you get to fight your team-mate because risks are very high and, as in every team, they warn you before the race: OK, you can try things on different people, but with your team-mate, please be careful - which is something normal," Leclerc explained to F1i.com.
"It's always obviously that something more. I had the opportunity and I didn't hesitate, I just sent for it. I was happy it was successful the first time I tried, especially after the bad start. So yeah, happy with how it ended up."
Leclerc did ignore team orders to pass Vettel, though, with the Ferrari team telling its new driver to hold position - but Leclerc replied with "But guys, I'm quicker!"