Hearts technical director Steven Naismith admitted they had been taught a “harsh lesson” as poor defending cost them in a 4-0 defeat by PAOK.

Hearts suffered a 6-1 aggregate defeat in the Europa Conference League play-offs on a difficult night in Greece.

Naismith told Hearts TV: “It was a harsh lesson. We created some good chances throughout the two games but when we give up goals that we have at this level with the quality of player, they are going to punish you, and that’s exactly what happened.

“We knew coming into it we had to be perfect defensively and we weren’t anywhere near where we needed to be, which kills the tie.”

Naismith highlighted PAOK’s third goal as the worst of the bunch. Kye Rowles saw the home goalkeeper’s kick go over his head and Giannis Konstantelias had time to mis-kick his first attempt from the resulting cross and still be able to stroke home unchallenged.

“The third goal is really poor, which inevitably kills the tie,” the former Scotland striker said.

“Overall, on tonight’s performance, the two things we need to learn from are the quality of chances we give up and how big an impact we are having on our own team, and secondly, we need keep the ball better.

“In the game early on we had glimpses of good passing moves which caused problems to them, but we didn’t do enough of it, they then dominate the ball, and we gave up poor goals.”