The Brazilians were held to a goalless draw by the Butchers in the 2018/19 Caf Champions League first round first-leg match on Sunday.
Mosimane had to do without several key players, who are out nursing injuries at the Petro Sport Stadium in Egypt.
“I think we can do better at home. We can seal it at home,” Mosimane told the media.
Injured trio Themba Zwane, Sibusiso Vilakazi and Denis Onyango missed the match which was played in Egypt as Libyan teams are not allowed to host Caf matches in their country due to security concerns.
Zambia international Kennedy Mweene started in goal in the absence of the club's first-choice goalkeeper Onyango.
“We have the time, we cannot be complaining about injuries. Kennedy did well, to be honest, maybe the back five including Kennedy did very well," the 2016 Caf Coach of the Year continued.
Phakamani Mahlambi started in the absence of Zwane and he impressed as the attacker kept the Al Ahli defence busy with his movement and dribbling skills.
Mosimane praised Mahlambi and Jeremy Brockie and he added that Sundowns will stand a good chance of winning at home in the second-leg clash.
"We had enough ammunition to still win, I am happy with Phaka (Mahlambi), " Mosimane added.
"Phaka played well, he is coming up slowly, JB (Brockie) is working hard also, it’s just the finishing touches, I think we will win the game at home,” he concluded.
According to the Caf website, Sundowns will host Al Ahli at the Loftus Stadium in Tshwane on Saturday.