Phil Smith's verdict: The key improvement Lee Johnson wants Sunderland to make as they take another big step forward
When the full-time whistle blew, seven agonising minutes of stoppage time survived, a number of Sunderland players fell to the turf.
There will have been some relief in there, for sure, but first and foremost it was just sheer exhaustion.
For this win, they had to suffer.
Which is not to say that they were fortunate, necessarily. Or that the three points were undeserved. They forged openings throughout, and had moments where they could have killed the game off.
But no one would argue with Ian Evatt's assessment that his Bolton Wanderers side could have got something out of the game, or his view that they had shown here why they can compete at the top end of the division this season.
In the second half they forged some excellent openings; Eoin Doyle uncharacteristically wasteful in front of goal.
In spells, Evatt's side showed a greater cohesion and fluency, unsurprising when you consider that they are a group much further down the line in their development than Lee Johnson's.
It was to Sunderland's credit that they found the defensive resilience they needed to get over the line, Callum Doyle and Dennis Cirkin again superb alongside the more experienced figures to their right.
Thorben Hoffmann again stood tall, the goalkeeper growing in stature with every appearance.
Johnson, too, felt that the game could have been won long before then.
At the start of the second half his side produced a wonderful flowing counter attack, one that should have yielded the all-important second goal. Alex Pritchard looked certain to score when he gathered Aiden McGeady's clever pass, but the attacking midfielder could only fire straight at Joel Dixon.
Johnson's high-risk gameplan had also yielded plenty of reward in the first half.
Bolton Wanderers are an attacking side and the Black Cats head coach knew they would have no intention of sitting deep.
He knew, too, than in players like Oladapo Afolayan they would have the capacity to cause problems in transition.
Johnson moved to put the pressure back on the opposition, his team's pressing game noticeably intense in the opening exchanges.
There were times when Bolton looked to be on the ropes, and they were fortunate that a knock to Dixon gave them a chance to regroup.
Johnson's response was to urge his players to find that intent again, urging his full backs to get higher and be more aggressive in their attacking play.
The reward was instant, a fine through ball from Elliot Embleton finding Cirkin at the byline. His cross was good, and the finish from Carl Winchester nerveless.
Though Bolton themselves offered a threat through the half, Sunderland ended it strongly and back on the front foot.
That there is much for Sunderland to improve on is clear and it was one of the key themes in Johnson's post-match comments.
He remains frustrated that the Black Cats are creating these tense ends to games, a consequence of not quite being ruthless enough in their forward play.
Part of that, he pointed out, stems from the fact that many of his players are still working their way up to full match sharpness having arrived late in the summer window.
The head coach still sees significant room for growth in the decision making on the ball and though proud of the result and the application, his mood was not buoyant.
"When you're a player and you want to win so much, the hardest thing to do is to have the fire in the belly and the ice in the head," he said.
"We had the fire in the belly today, but not quite enough of the ice in the head.
"In saying that, we have had three or four breakaways and we should have been more potent.
"It's a game where we have learned a lot, we can go back and evaluate our performances both as individuals and as a team, but we get to do that with three points in our back pocket."
But even in these areas where this is much work to be done, you can see the improvement.
Substitute Leon Dajaku had two good openings to get on the scoresheet, both of them coming at the end of a precise and composed Sunderland move.
Johnson was eager, too, to ensure that desire for more did not prevent his players enjoying what was a superb result.
Given the scale of the summer overhaul that took place on Wearside, a haul of 19 points through eight games is a quite outstanding return, particularly when you consider that they have faced many of the early form sides in the division.
That in particular is a point not lost on the Sunderland boss.
“The boys have been great," he said.
"They deserve so much credit.
“Rewind to the articles that were in the paper sort of two or three weeks before the season started and there was a lot of anxiety around the club. A lot of anxiety in the fanbase.
“The players have dealt with that fantastically well. They’ve worked ever so hard in pre-season, we've trusted the young players and the young players have come to the fore.
“The likes of Dan Neil, who I thought was absolutely fantastic today.
"I knew we were good. Even our pre-season form was good, we beat teams like Hearts, we beat teams like Harrogate that we knew was a good side. We beat Hull so you get a feel for what your team is and what your team isn’t.
“I was desperate like we all were to bring in more quality, because we know how tough the longevity of the season is."
That Sunderland can still improve from this position of real strength is a prospect building considerable excitement.