- Cristiano Ronaldo (66')
- Anderson Talisca (72', 77')
- Senin Sebai (44')
Home favourites Al Nassr dominated the first half, but were impossibly kept off the scoresheet in the opening 45 minutes and found themselves down 1-0 to their Tajik foes after Senin Sebai scored with his team's first shot just before the break.
The frustrations continued for Al Nassr until Ronaldo finally scored an equaliser for the hosts -- netting for the seventh consecutive game -- as he pounced on the rebound from his own blocked shot and chipping Istiklol keeper Rustam Yatimov.
Anderson Talisca added two more within five minutes soon after Ronaldo's opener to complete the comeback and maintain Al Nassr's perfect record in the early stages of the ACL, having taken six points from their first two matches.
Iran's Persepolis are in second place behind Al Nassr following a 1-0 win over Al Duhail of Qatar, with Omid Alishah scoring in the 63rd minute to earn the 2018 and 2020 runners-up their first victory of the campaign.
Elsewhere, Nasaf Qarshi of Uzbekistan maintained its perfect start in Group B with a 3-1 win over Qatar's Al-Sadd, while Al-Faisaly lost 1-0 at Sharjah.
Only the 10 group winners and the six best-performing runners-up will progress to the next stage.
- Ko Hyung-Jin