The UAE Pro League outfit fell behind in Tuesday's first leg when Anwar Al-Hinai found the net in the 39th minute, but claimed a potentially crucial away goal when Leandro Lima tucked home a penalty on the hour.
Ivan Jovanovic's side warmed up for Wednesday's second leg by thumping Dubai 3-0 away from home on Saturday to finish their domestic season in fifth place, an agonising one point away from qualifying for the AFC Champions League.
Al Nahda, meanwhile, have tasted glory on the domestic front this season, and have already been crowned champions of the Omani Elite League.
They lead second-placed Fanja by five points with only one match remaining, and they may benefit from having an extra four days' rest over their opponents, having not been in action since the first leg of the tie.
The two sides meet at the Rashid Al-Maktoum Stadium in Dubai and the winner will progress to the final against either Saham and Al Shabab, with Saham leading 3-1 from the first leg.
