Isa blew the best chance to give the home side an advantage heading into the second leg in Wellington on Nov. 14 when he rounded goalkeeper Mark Paston in the 75th minute but his shot slammed into the post.
He could have easily squared the ball to an unmarked Jaycee John who, along with his team mates, expressed his frustration at the midfielder for missing the gilt-edged chance.
Fouzie Aish and Muhammed Huibial prompted good saves from Paston while John's 84th-minute shot was deflected away following desperate defensive lunges by Ben Sigmund and captain Ryan Nelsen.
The tiny Gulf nation are bidding to qualify for their first World Cup finals after finishing fifth in the Asian confederation following a playoff victory over Saudi Arabia.
However, the advantage may now have shifted towards Oceania champions New Zealand, who are seeking to make the finals for the first time since 1982.
Marshalled by Blackburn Rovers captain Nelsen, the All Whites defended well and while they were exposed from time to time by the speedy Bahrainis, Paston was truly tested only three times.
New Zealand also had several chances late in the game and a late strike by substitute Chris Wood was ruled out for offside.
Neither team dominated in the first half. John's shot that sailed wide of Paston's left-hand post in the 20th minute and Husain Ali Baba's shot into the side netting five minutes later were the best opportunities.
