After having a huge say in the top four race — with back-to-back wins against Arsenal and Tottenham — the Seagulls are now set to travel to the Etihad, where they could dent Manchester City's title hopes.
Lallana, a second-half substitute against Spurs, said: "It's remarkable to go back-to-back in North London. I'm not sure I've been a part of that in my career.
"Credit to the boys today.
"There's a feel good factor in coming to London. The suns out and it's a nice spring afternoon.
"Tottenham are a top team. We will take a lot of confidence from today."
Lallana said the final stretch of the season is 'going to be interesting'.
He added: "We've done them [Arsenal and Tottenham] both a favour.
"We can't be biased.
"It's wide open. It's a great year in the Premier League.
"There's tough teams week in week out. We are one of them [and have caused] upsets this year against big teams.
"Hopefully we can get one more on Wednesday night against City for my old team."
Lallana was delighted with Albion's upturn in form, as they extended their unbeaten run to three games since the international break in March.
"The last three performances have been nothing short of excellent," he said.
"It was a great two weeks to reset and get back to basics [after six successive defeats].
"We had a good couple of meetings. We have set our standards. There's no reason why we shouldn't be performing to that level, attitude and desire week in, week out.
"There's lots of positives but there's always room for improvements."