Sueoka, who replaced Reisangmei Vashum in the 55th minute, brought the 40,000-odd crowd on their feet with a 71st minute strike as his curling shot from the edge of the box found the Semen Padang net.
Eyeing their maiden semifinal berth, East Bengal will face the Indonesian outfit in the return-leg of the quarterfinals at the Agus Salim Stadium in Padang on September 24.
Goan heavyweights Dempo FC are the only Indian side to have made the AFC Cup semifinals in the 2004-05 season.
The red-and-gold brigade did not have a convincing start as they relied on long balls. To make matters worse, Sudanese recruit James Moga did not look fully fit. The visitors dominated the first half which failed to yield any goal.
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In fact, things could have been different had Padang not missed two easy sitters early into the match.
East Bengal survived an early scare and full credit should be given to goalkeeper Gurpreet Singh who stood tall under the bar, thwarting two back-to-back attempts from the Indonesian outfit.
Minutes later, East Bengal camp once again panicked but came out lucky with the Padang outfit wasting a sitter. Yu Hyunkoo tested Gurpreet with a shot that dipped a lot and the rebound fell in front of Ronaldo Moro whose angled header in front of the goal was wayward.