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.
"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.
"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."
