Northern Ireland coach Michael O'Neill was disappointed with his side's 1-1 draw with Luxembourg in Belfast on Tuesday.
The home side went ahead in the 14th minute through Dean Shiels and dominated the match thereafter, as they had three goals disallowed and also hit the post once.
However, Luxembourg stole the equaliser in the 86th minute at Windsor Park when Daniel da Mota's effort from close range deflected off Ryan McGivern into the hosts' net.
"I am very disappointed," O'Neill told Sky Sports. "We had enough chances to win.
"In the second half we let our standards drop. Our energy levels dropped too."
O'Neill was also not impressed with the performance of the match officials, who ruled out three Northern Ireland goals and gave more than 10 offside decisions against them.
"The game was disrupted by offside calls," lamented O'Neill. "There were too many free-kicks and too many disruptions."
Northern Ireland have now picked up just one point from their opening two Group F games and will take on Portugal next in October.