The combative striker, who joined Wigan from Zamalek on a season-long loan, pulled one back for the visitors after West Ham led by two goals from Dean Ashton.
In the 47th minute, Zaki received Emile Heskey's flick with a powerful left-footed volley that went into the roof of the net.
Zaki was a constant threat throughout the game. He could have secured a precious equalizer on several occasions.
Six minutes past the hour mark, the Egypt frontman was picked out unmarked by Wilson Palacios' neat cross at the far post but his header missed the target.
Zaki, nicknamed the Bulldozer, had another decent effort two minutes later but his volley from inside the area flew high over.
The 25-year-old almost leveled the score in stoppage time but his right-footed shot went over the bar from eight yards out.
However, it remains a perfect start for Zaki, who is in line to make his second competitive appearance against Chelsea at the JJB stadium next week.