Al Ahly of Egypt stretched their unbeaten run to 50 games with a goalless draw against Etoile Sahel in the first leg of the African Champions League final in Sousse.
Ahly are now favourites to land a second Champions League title in four years and scoop the million-dollar prize money.
Etoile Sahel, who were beaten in last year's finals by Enyimba, were thwarted by Ahly's tight defending throughout the game, though both sides failed to convert any chances.
Ahly looked the stronger side especially in the first-half but Mohammed Barakat and Hassan Mostapha could not find the back of the net.
But it was Etoile who came close to scoring just before the break after a mistake by Ahly goalkeeper Essam Al Hadary, but teenage striker Gilson couldn't keep his overhead kick on target.
Ahly's chance to break the deadlock came in the 65th minute when Hassan Mostafa dribbled past two defenders before shooting wide from the edge of the penalty area.
The decisive leg of the Champions League final will be played in Cairo on 12 November.
It promises to be a tense encounter as both sides also have an eye on participating in the revived World Club Championship in Japan in December, where the financial rewards on offer will boost the coffers of the eventual African champions.