Newcastle manager Steve Bruce told BBC Sport: "We gave ourselves a mountain to climb. We've gifted them the first two goals. When you start like that it'll be a difficult afternoon.
"We changed formation at half-time and it helped us slightly but we couldn't recover from an awful 10 minutes. Since I've been here it's like this. We do OK for a while, then we throw a hand grenade in. We've got to be better than we were today."
On Yves Bissouma's red card: "I don't know what the lad is doing. He was showboating before that and it's a nasty cut [to Jamal Lewis]. But it's not the cut we're worried about. He's got an abrasion on his eye, we think. By the letter of the law it's pretty obviously dangerous, I don't know why he's doing it when he's left a mess like that. I don't think he intended it but it's stupid."
Brighton manager Graham Potter told BBC Sport: "I'm delighted with the start. It reflects the attitude the players have had all week.
"To keep a clean sheet and score three goals, creating a few more opportunities and limiting our opponents to not much was positive. I'm delighted for the players. It's good to get up and running in the Premier League."
On Lamptey: "He's so refreshing to work with. He threatens the back line with such pace but he also the desire to do it. He's a fantastic boy who wants to improve and help the team. He's a breath of fresh air since he has come in and I am delighted for him."
On Bissouma's red card: "Knowing Yves there won't be any intent so it's whether it's an uncontrolled action. It's the one disappointing bit of the game. We're 3-0 up, there's no need for Yves to hurt the player - he's not that type of player anyway."