Sunderland fell 2-1 after taking an early lead.
"I think it was our best performance of the season in the first half," Ki told the Evening Chronicle. "The boys tried really hard to press the ball, squeeze them up and we scored a goal.
"We had good chances in the first half, but we did not take score them.
"Maybe that is the difference between the top teams and the rest - when they have the chances, they score."
For breaking stories and all the great banter like us on Facebook: facebook.com/tribalfootball