The Koreans dominated the match for 85 minutes and led comfortably thanks to two goals from Jeju United's 21-year-old midfielder Koo Ja-cheol which were both aided by mistakes from the Gulf side.
Faouzi Aaish then made it a needlessly nervy last five minutes for the Koreans after he converted a penalty following defender Kwak Tae-hwi's dismissal for bringing down substitute Abdulla Al Dakeel in the area.
However, the twice Asian champions resisted the pressure to record a fully-deserved win in front of the watching AFC president Mohamed Bin Hammam at a chilly and two thirds empty Al Gharafa Stadium.
"We could have been better if we avoided the situation of the penalty kick but we do have three players to cover the position (for the next match)," Korean coach Cho Kwang-rae told reporters.
The 6,669 that did attend saw the Red Devils take the lead five minutes before halftime when Koo's right-footed strike near the penalty spot was deflected past Bahrain goalkeeper Mahmood Mansoor by his team mate Abdulla Marzooqi.
The second came seven minutes after the break when Mansoor could only parry Cha Du-ri's dipping 20-metre drive back in front of his goal to allow Koo a simple tap in from inside the six-yard box.
Bahrain offered little in attacking threat throughout the match with their coach Salman Shareedah providing the most entertainment.
The recently appointed bespectacled coach prowled the edge of his technical area as if trapped like a mime artist, demonstrating various frustrated poses in his grey suit.
He was given hope, however, when central defender Kwak fell into Al Dakeel with the referee producing a straight red card and awarding the penalty.
"You must remember that I have only spent two months with the team," a more subdued Shareedah told reporters. "We will try to raise the moral for the next two matches."
The Koreans have qualified for seven successive World Cups but have struggled in the 16-team regional competition after winning the first two editions in 1956 and 60.
Their fans will hope that wait is coming to an end after a confident display against a side who narrowly missed out on qualifying for the last two World Cup finals in playoffs and had been expected to cause them problems.
The opening victory puts the Koreans on three points in Group C, level with Australia who earlier thrashed lowly India 4-0 at the Al Sadd Stadium.
