West Ham manager David Moyes, speaking to TNT Sports: "I'm really pleased that we got the result because the result was the most important thing.
"We didn't play as well as we would have liked but they're a decent team and a well seasoned European team and used to coming away in these competitions - more so than we are.
"In the end I think we were the ones who made the best chances, they didn't have too many chances to score. It was a little bit hairy towards the end, but largely we controlled it."
On his team's winning goal: "It was a lovely ball by James [Ward-Prowse] and also the finish from Lucas [Paqueta] was great.
"We had two or three chances and we didn't take them any of them, we didn't have many but you don't get too many chances in these games.
"Thankfully Lucas came up with the goal.
"I'm pleased for him because he does a lot of good things which go unnoticed, he also did a few things which weren't as good as we would like, but he made up for it with the goal.
"We tried to play in the right areas and get the ball into the final third, but when we got in there we didn't really make enough opportunities, or make runs behind or threaten enough with crosses. But that's a lot of credit to Olympiakos.
"We felt we let ourselves down [in Greece] and wanted to put it right. Let's hope we can continue that form."