Moyes later said: "It was a little bit typical of an away tie at the knockout stage.
"We were trying to make sure we gave ourselves a really good result here to go back to London Stadium and I thought for long periods it was going to be that way.
"But we turned the ball over terribly for the goal when really we hadn't given them too many opportunities in the second half.
"We didn't play particularly well in the first half and I wasn't happy with them at half-time, but we improved in the second half and we just didn't have our shooting boots on tonight.
"We missed three or four big chances and all the players had chances from Mo to Jarrod to Lucas, all had opportunities, but we just didn't connect with them tonight.
"We had actually grown and were getting better and if anybody was going to score at that period in the game if was actually probably us.
"We've missed chances. Jarrod missed a chance in the first half when Mo played him, Paquet had a header at the back post, and then the 'keeper made a big save from Jarrod, so we had big opportunities tonight.
"Then we had a penalty claim at the end which on other days might go for us but it didn't tonight.
"There were so many things on the pitch that felt as if we didn't come out on top on all of them. We were second to every ball tonight and I don't know if we're frightened of the way referees referee games sometimes, but we came out second on so many things and we ended up losing the game narrowly.
"But we have a chance in the second leg, that's for sure.
"We'll need to play better next week than we did tonight.
"I was really surprised we didn't reach the standards and some of the players were below where we would expect them to be.
"We gave the ball away far too much and in Europe it's more difficult (to get it back).
"In the second half we played much better and created some opportunities and found things, but the goal was a sickener, to be honest."