Great Britain once more left their fightback too late as they slipped to a 12-8 defeat in the first Test against New Zealand in Auckland.
The teams were level at 2-2 at half-time, but the tourists were hit by two tries in six minutes to go 10 points behind and posed their only real threats in a frantic last 15 minutes.
Replacement hooker Daryl Clark went over for a try to give them hope of a first win in New Zealand since 1992 and winger Jermaine McGillvary touched down at the corner four minutes from the end only to have the score disallowed for a knock-on.
Despite the thrilling comeback, it was another disappointing performance from Wayne Bennett's men, who were lacklustre in an opening 14-6 defeat by a Tongan Invitational XIII in Hamilton a week earlier.
The Lions will have a chance to square the series with the Kiwis in Christchurch next Saturday, but they will be haunted by the feeling that their hosts were there for the taking at Eden Park and that this was a glorious opportunity missed.
New Zealand coach Michael Maguire had responded to his team's 26-4 defeat to Australia by dropping playmaker Shaun Johnson in favour of the equally experienced Kieran Foran, but his comeback lasted only five minutes before he went off with a dislocated shoulder.
And the Kiwis played the game without a specialist hooker after Maguire sprung a last-minute surprise by axing Brandon Smith for a breach of team protocol and bringing in half-back Kodi Nikorima, who was not even in the 24-man squad.
The Lions clearly heeded the message from Bennett as they kept their errors to a minimum - it was 34 minutes before they came up with a first handling error - and they had most of the possession in the first half.
The introduction of full-back Jonny Lomax added more thrust to the attack, while his St Helens team-mate Alex Walmsley made a big impact from the bench.
But there were too many tame endings to their sets and the only scores before half-time came from penalties by Jamayne Isaako (New Zealand) and Gareth Widdop (Great Britain).
The Kiwis produced an error-strewn first half but still managed to create the only tryscoring chances, with centre Joseph Manu failing to finish off a break by Benji Marshall and former Leeds winger Ryan Hall coming to the rescue by intercepting Jerome Hughes' pass near his own line.
The breakthrough came eight minutes into the second half, when full-back Roger Tuivasa-Sheck wriggled free of Walmsley's tackle to get Isaako racing away for the opening try.
Three minutes later, second rower Briton Nikora touched down a Marshall kick only to have the try disallowed for a knock-on in the build-up, but the reprieve was short-lived as substitute Corey Harawira-Naera used brute force to get the ball over the line despite the attention of four defenders.
Isaako kicked his second goal to open up a 10-point lead and Britain started to come up with the errors as they began to chase the game.
Clark brought them back into the contest on 68 minutes when he finished off a drive by Walmsley to score their only try and Widdop added the conversion before McGillvary's close shave, when he lost his grip on the ball in Kenny Bromwich's last-ditch tackle.
Great Britain experienced more injury woe as they suffered a second successive defeat on their tour of New Zealand.
Beaten by a Tongan Invitational XIII in their first outing for 12 years in Hamilton a week earlier, the Lions are now 1-0 behind in their two-match Test series with New Zealand after going down 12-8 in Auckland.
To compound their misery, they lost England's record try-scoring winger Ryan Hall with a knee injury.
"I think he's dislocated his knee which he did earlier in the season," coach Wayne Bennett told the post-match press conference. "It's gone back in but it did come out, so he said."
Hall, who left Leeds 12 months ago to join Sydney Roosters, missed the Test series against the Kiwis in 2018 after undergoing major knee surgery and has been restricted by injury to just six NRL appearances in his first season with his new club.
Bennett chose only two specialist wingmen in his 24-man squad and so is facing a selection headache for next Saturday's second Test in Christchurch.
Asked if he would consider bringing in Wales winger Regan Grace, Bennett said: "I don't know if we can bring other players in. I don't think we can but I'm not sure."
Britain lost centre Oliver Gildart with a tour-ending shoulder dislocation in the defeat in Hamilton and Bennett does not expect prop Luke Thompson to feature again on the tour after struggling with rib cartilage damage sustained in the same match.
The Lions end their tour with a Test against Papua New Guinea in Port Moresby on November 16 but more immediately will be ruing another fightback that came too late.
The teams were level at 2-2 at half-time, but the tourists were hit by two tries in six minutes from Jamayne Isaako and Corey Harawira-Naera to go 10 points behind and posed their only real threats when it was too late.
Replacement hooker Daryl Clark went over for a try to give them hope and winger Jermaine McGillvary touched down at the corner four minutes from the end only to lose the ball in Kenny Bromwich's last-ditch tackle.
Bennett remained upbeat, putting the defeat down to "a little bit of luck".
"It was a tight game, there was nothing in it all afternoon," he said. "We probably should have had two tries in the last five minutes but we didn't get them and they managed to keep their nose in front.
"The first half was a pretty dismal game of football to be honest with you. Completions were high but there was just nothing happening out there.
"We sorted a few things out at half-time and we stuck to it in the second half.
"Our halves could have been on the ball a lot more in the first half than they were but they got that right in the second half.
"There was a lot more ball movement and played a lot better football to give ourselves a chance."
Asked if he was concerned about his team managing just two tries in two games so far, Bennett said: "I'm not going to lose any sleep over that.
"The opposition only scored two as well. The bottom line is no one is scoring a lot of tries.
"Last week we didn't make any opportunities to score tries, today we had opportunities to score tries so that's the difference.
"We're on the up, we're not going backwards and we played a quality team out there today."