Joe Root’s hosts were booked for a miserable defeat inside three days, probably by an innings, when Buttler (66no) and debutant Bess (55no) joined forces still 69 runs in arrears on a second-innings 110-6.
But they gave the Lord’s crowd, and home dressing-room, a much-needed lift with an unbroken stand which took England to 235 at stumps against Pakistan.
The lead is still only 56 after a woeful start to this series opener for the hosts.
Buttler, fresh back from the Indian Premier League for his first Test in 18 months, and 20-year-old Bess defied all expectations - batting through the evening session after Root’s dismissal for 68 completed a damaging sequence of four wickets for the addition of just 19 runs.
“Of course there is (belief we can win),” said Buttler.
“The atmosphere in the ground was great there at the end, and of course in the dressing-room as well.
“A fourth-innings score, chasing down a total, is never going to be easy - if we can get our way up to a challenging total.”
With the resourceful and confident Bess for company, he is prepared to aim high too.
“Tomorrow we need to make it as big as we can,” Buttler added.
“One hundred and 50 would be great, (but) we’d probably be trying to think more like 200.
“I know that’s a lot more runs, but 200 in the fourth innings will be tough. If it’s 150, that’s going to have to be enough.”
Buttler never met Bess before he left Somerset for Lancashire five years ago, but has since been kept up to speed about the youngster’s developing all-round talent during his rapid rise through the ranks at Taunton.
“I haven’t seen him bat much, but I’ve heard a lot about his batting from the guys at Somerset,” he said.
“He can obviously bat. It was a bit like Joe Root, some of those back-foot punches and cover-drives.”
That is high praise indeed, although perhaps Bess’ most important quality is the optimistic can-do attitude which had him dropping broad hints at a pre-match press conference about possible IKEA endorsements - after new national selector Ed Smith interrupted his furniture shopping last week to tell him of a surprise maiden Test call-up.
Buttler said: “You certainly wouldn’t think it’s his first game, trying to get a free sofa from IKEA, and all that!
“He’s really taken to it. He’s got a great character, and I think he really loves the competition.
“He’s got some really good attributes, which you need in international cricket.”
Bess demonstrated many of them, including a very workable technique.
“We were both just trying to scrap hard for the side,” his senior partner added.
“He’s got a lot of fight, and he was trying to show that - and for me, being back in the side, I was showing how much it means to be out there.”
Pakistan still appear to be well ahead of the game, but are wary of England.
Key batsman Asad Shafiq said: “We won’t be happy to chase anything over 150.
“I don’t think we did anything wrong.
“We should give credit to the English batsmen, especially the debutant.
“He played really well, and the way he and Buttler battled gave them a really good partnership.”