Gregor Townsend's side needed to recover from a poor opening defeat by Ireland, whose subsequent loss to Japan was a further blow to their chances.

But first-half tries from Sean Maitland and Greg Laidlaw and a Stuart Hogg drop goal put the Scots in command in stifling conditions in Kobe, with two penalty tries after half-time ensuring the extra point they craved.

The Scots now move up to third in the Pool A behind Japan and Ireland after two games each.

Townsend's team handle heat on and off the pitch

Under the closed roof at the Misaki Stadium, the conditions were as hot and as steamy as a sauna, as stifling and as suffocating as a greenhouse in the Edinburgh Botanics on a hot summer's day. The ball was slippy and passes went down. Lots of them. The organisers of this World Cup have erred here. Enclosing this ground was a strange call.

Scotland endured the most miserable week, but had an anger and a focus about them that stood out a mile. They promised a reaction to the awful loss against Ireland and it was obvious from early on that they were going to deliver it. A new wing, a new centre partnership and a whole new back row, the Scots had energy and aggression by the bucketload, the very qualities that were desperately lacking in their opening game in Yokohama.

That fourth try came late, but it was deserved. Scotland kept their nerve and produced a stirring performance, the kind of battling effort that marks them out as not quite dead in this pool. It was an extraordinarily nervous and difficult night in the conditions, but they emerged. They had to sweat, literally and metaphorically, but they showed huge character and hunger and got the job done.

They went ahead early through a Laidlaw penalty and took a firm hold of the Test. They won the collisions, an absolute must against Samoa, and even though their early dominance took a while to get converted into points, they always looked threatening. The bar of soap that passed as a ball was part of the problem. All night, catching the thing was a challenge.

Scotland's players struggled with their handling in the stifling heat in Kobe

Scotland had a fury that was best represented that new back row. Magnus Bradbury, Jamie Ritchie and Blade Thomson carried hard and often. The Scottish pack felt almost humiliated a week but now they were inflicting some damage of their own. Grant Gilchrist, who spoke emotionally of the "dark place" that the Scots had inhabited for a week, was also a thumping presence in an overwhelming pack.

Their first try came on the half hour and it arrived when Scotland used their aerial game, first with Laidlaw's kick that Samoa struggled to deal with, then a Garryowen that caused more confusion in Samoan ranks. The third boot to ball was Russell's cross kick, off a free play, to Maitland who slipped out of Tusi Pisi's despairing lunge to score.

Laidlaw's conversion gave Scotland a handy 10-point lead. Within five minutes they'd added to it. Russell went though a half-gap and found Ritchie with a cheeky offload. The flanker ran on and found Laidlaw who bounced out of Tim Nanai-Williams' attempted tackle to run in at the posts.

The scrum-half added the conversion before Hogg kept the scoreboard ticking with a booming 40-metre drop goal. Hogg punched the air when his kick sailed up and over. Scotland had at last found themselves.

Scotland liberated from their demons

Samoa were a major disappointment. They offered bravery in defence but nothing in attack. Their best work was done inside their own 22 when scrambling to keep the Scots out. In the final minutes of the opening half they had to fight to avoid conceding a third score when the Scots had a series of lineout mauls, all of them collapsed. The siege was eventually lifted, but Samoa looked a jaded team when that half-time whistle was heard.

At 20-0 the game was done, the biggest task for Scotland being the pursuit of the four-try bonus point they needed so badly. They had chances, so many chances. Russell overthrew a pass to Darcy Graham in a good position, then grubbered to Graham, but that one went south as well.

Samoa eventually caved in. The Scots drove a lineout - their maul caused a heap of trouble all night - and when Fraser Brown looked to have gone over, referee Pascal Gauzere went to his TMO for a closer look. What they saw was Fidow's side entry as Brown went for the line. Penalty try and a yellow for Fidow.

The Scots now needed a single try for that precious bonus and had 25 minutes to get it. Gordon Reid saw glory in grasp and stretched out for a touch down that never came. The prop spilled it. More time ticked by. Seven minutes left now.

Samoa were in Scotland's half. Ulupano Seuteni tried a penalty to touch that would have wound the clock down but made a mess of it and kicked it dead. Respite for the Scots, who charged downfield. The endgame was dramatic as Townsend's team pushed on up the left.

Thomson carried heroically and put Samoa on the back foot. Russell picked it up and Scotland moved on. Maitland was put clear up the wing, dived early for the line under pressure from Fidow and lost possession. The Scottish supporters sank to their knees and then promptly got to their feet when Gauzere got involved.

Gauzere penalised Fidow for clattering knees-first into Maitland as he went for the line. A second yellow - which meant a red - for Fidow and a second penalty try for Scotland. A five-pointer won in the most heart-stopping circumstances. Liberation from the demons of a week ago and much-needed hope in the weeks ahead.

Triumphant Scotland face Russia in their next pool A Test