When Chelsea misfit Andriy Shevchenko flashed home an equaliser for Ukraine, who were trailing to Peter Crouch's opener, that familiar Wembley gloom started to descend.
It took Terry to raise the roof, smartly steering home Steven Gerrard's knock-down from a trademark David Beckham free-kick to make it five Group Six wins on the trot for Fabio Capello and his boys.
Capello's double-fisted victory celebration emphasised the importance of Terry's goal.
As Wednesday night's opponents must meet Croatia on June 6, the same day as England take on Kazakhstan, the Three Lions will return to base to face Andorra four days later knowing their place at the biggest stage of all could be virtually secure four months ahead of schedule.
This was not a fluent England performance. There was too much hesitancy and too many unforced errors for that.
Full-backs Glen Johnson and Ashley Cole were among the culprits, so too was Steven Gerrard, who needlessly gave the ball away close to his own area; not that the Ukraine side could take advantage.
Most obvious though was David James' misread of Anatoliy Tymoshchuk's long-range shot which bounced off his shoulder.
Sixteen months ago against Croatia, Scott Carson made the same kind of blunder and the ball squirmed in. This time it bounced kindly for John Terry, who blasted it out of the England penalty area.
Capello has proved to be better than McClaren in a number of areas. Crucially, it seems he also enjoys better luck.
England were already in front by that stage, thanks to one of the flashes of inspiration which were the opening period's staple diet.
Wayne Rooney provided it with a deft flicked header that bounced wide off a defender to earn England a corner which Frank Lampard dropped on to the head of Chelsea team-mate John Terry.
The England skipper could not get enough power into his effort to cause any damage himself. What he did manage to do was guide it into the path of Crouch, who turned smartly and let fly with a six-yard volley which cannoned into Andrii Piatov before zooming into the net.
Crouch milked the celebrations as he had every right to do. There was even the little dance, the 'Rope Pull' suggested by James Corden in Comic Relief, showing that life under Capello is not the rigid regime it is made out to be.
Yet if the Portsmouth star's 15th international goal was the tangible evidence of England's bright new world, the performance of Rooney was a pretty spectacular supporting act.
Although there were occasional glimpses of frustration when England's approach work did not match his expectation, they were outweighed by moments of pure genius.
The overhead kick that brushed the roof of Piatov's net after just seven minutes was awesome in its simplicity and he looked well set to burst clear inside the Ukraine penalty area when he was mercilessly chopped down on England's next attack.
Gerrard must love playing with him. Certainly there is not even the merest suggestion of discontent about being shoved out of the role he fulfils so well himself for Liverpool.
How can Gerrard complain anyway given the number of times he gets to drive into acres of space from his left-side station thanks to one of Rooney's magic interventions.
It was Gerrard who curled the free-kick narrowly wide after Rooney had been upended. The Liverpool star also got on the end of Rooney's low cross at the end of the half, only for Piatov to make a solid save to repel the side-footed shot.
The belated introduction of Shevchenko 10 minutes into the second-half offered the visiting fans something to cheer, even, as if to ensure the Ukrainians were drowned out, Capello responded by bringing on David Beckham for his 110th cap.
By that point, Rooney had embarked on another startling run which began just inside the visitors' half and left four defenders trailing in his wake before his shot fizzed wide, Piatov uncertain whether he needed to try and keep it out or not.
Rooney continued to sprinkle the game with his unique talent. Unfortunately, after two years at Chelsea doing little to justify his £30million price tag and vast salary, Shevchenko finally did something worthy of his reputation.
Shevchenko's instinctive finish looked like wrecking England's 100% record. After 24 ill-fated months at Stamford Bridge, he should have known Terry a bit better than that.