Everton, needing three points to secure survival, took an early lead through Dominic Calvert-Lewin but things unravelled after teenage defender Jarrad Branthwaite saw red for denying Ivan Toney a clear goalscoring opportunity soon after.
Brentford drew level through Seamus Coleman and though Richarlison’s penalty put Everton ahead in first-half stoppage time, the extra man told after the break as two goals in three minutes from Yoane Wissa and Rico Henry won it for the visitors.
Everton’s woes were underlined when substitute Salomon Rondon was shown a straight red late on for a poor challenge on Henry, with frustrated fans quickly pouring out of Goodison Park.
But Lampard has urged his side to bounce back for Thursday’s visit of Crystal Palace when the Toffees have another chance to secure safety.
“Down is not a problem,” Lampard said. “It was the circumstances of the game. Down is normal, we want to stay in the league. Everyone saw the intention of the team from the first minute to last.
“Down for a day is fine. Rest a bit (on Tuesday), be positive and everyone get together from the club like we did. That’s the beauty of it being in our hands.
They just need to rest and go again with the same desire, hopefully with 11 men through the game.
“Outstanding effort, the game plan before the game – brilliant. The period when it was 11 v 11 it felt like we controlled the game and we should have scored more against a really good side. It’s really hard to say anything to them after that.”
Lampard feels picking up the players for the final two games should not be a problem given the stakes.
“I don’t think so,” Lampard said. “Everyone understands the game. If I sat here and it was 11 v 11 and we went 1-0 up and lost 3-2 you can ask me about why it went wrong tactically or individually.
“They just need to rest and go again with the same desire, hopefully with 11 men through the game.”
Branthwaite had stepped into the side due to an illness for Michael Keane, who Lampard expects to have back for the final two games.
Brentford could have another big say in the relegation scrap on the final day of the season with Leeds – one point behind Everton and one clear of 18th-placed Burnley having played a game more than both – due in west London next weekend.
Thomas Frank said his side’s performance at Goodison Park answered any critics who suggested they had nothing left to play for, and promised it would be the same next Sunday.
“Oh, I think we will put the ‘B’ team out,” he joked. “Of course, we put the very best team out. We understand we need to do our best to win. It’s nothing about Everton, Burnley or Leeds.
“We want to do our best to try and win on Sunday. If Brentford can finish in the top 10 that’s what I want. I understand there’s also a few quid to gain if we finish higher.
“Maybe after you’ve been 10 years in the Premier League you don’t care if you finish 11th or ninth but for us every game is a cup final.”