The Malian outfit were aiming to make the most of home advantage at the Stade Modibo Keita in the first-leg encounter.
Yet it was the Tunisian side who drew first blood in the tie, Haythem Jouini making the breakthrough in the 27th minute.
The visitors held onto their lead until the break, and it looked as though ES Tunis would maintain their one-goal advantage ahead of Friday's return leg.
However, Moussa Doumbia restored parity 12 minutes from time to leave the tie nicely poised.
In Saturday's other second qualifying round match, Nkana's hopes of progressing were hindered by a 0-0 draw at home to Egyptian outfit Zamalek.
The Zambian hosts applied plenty of early pressure at Nkana Stadium, but failed to build on their promising opening and face a difficult task against Mido's men in the return leg.
‘Maybe I’ll be signed by Wrexham, who knows? English football would suit me – if an offer came, I wouldn’t think twice, I’d go immediately’ Euro 2024 cult hero reveals his UK dream
‘Managing Leeds? It was an option that appeared, but it wasn’t the right timing. I decided it wasn’t a good idea to leave the club I was at mid-season’: Premier League boss admits to turning down opportunity to replace Jesse Marsch in 2023
