Win first toss: check. Score first hundred as captain: check. Bat through to the close: check. Joe Root stepped into the breach with England in a familiar spot of bother on the first day of the series and produced an equally familiar response to repel South Africa at Lord's. If Root might have preferred his scriptwriters to provide a more solid base from which to begin his work in charge of the Test side, he could have barely a quibble with how his own day progressed.

South Africa, on top after a morning session in which they claimed four wickets, contributed generously to Root's cause. He was missed twice early on in his innings and then, during the evening session stumped off a no-ball; no sooner had Keshav Maharaj's mistake been broadcast on the big screen, then Root was heading back to his crease for more. His next delivery was tapped through the covers for a single to bring up his 150, as cries of "Rooooot!" rolled down from the stands once again.

On a glorious day with all the Lord's trimmings, Root forged century stands with Ben Stokes and Moeen Ali to ensure England's new regime got off to an fittingly exuberant start. Vernon Philander claimed three early wickets but mistakes crept into the South African effort. Root was not the only England batsman to benefit from being dismissed off a no-ball, with Stokes reprieved by an on-field call as Morne Morkel overstepped by a distance, also from the Nursery End.

Stokes was not able to capitalise fully, top-edging a pull off Kagiso Rabada after tea to depart in frustration for 56. Rabada was the unlucky bowler on both occasions during the morning session with Root was given left-offs on 5 and 16; when he thought he might have had Root taken in the gully, after raising his fifty, South Africa's review only succeeded in proving it had come off the batsman's helmet (with Rabada's boot right on the margin of delivering another no-ball).

Having dug in to reach lunch on a dogged 33 and then steadily battled through to take tea on 79, Root moved through the gears during the evening session. Twice Rabada was left huffing as Root steered fours to third man to move into the 90s, before a dab for three off Maharaj made him the fourth England captain in succession to start his tenure with a century. His next fifty came off just 43 balls, including lofting Maharaj down the ground for six, and by the close he had skipped to the highest score by an England captain in their first Test.

Things had not started so well, as England slipped to 49 for 3 and then 76 for 4 - a change of leader failing to imbue any greater degree of top-order stability - before Root and Stokes, newly installed as vice-captain, began the counter, adding exactly 100 together during the middle session. It was a similar response to when the effervescent pair lifted England from trouble on this ground against New Zealand two years ago, although they were made to work harder for their runs against a South Africa attack that was always threatening, despite the indiscipline.

Stokes got off the mark with a clipped four through midwicket from his first delivery, and showed his touch with a crisp straight drive off Morkel after lunch, but his innings was an unusually watchful affair. He planted Maharaj into the pavilion benches midway through the afternoon and was a little fortunate to clear mid-on running back when he had 26; the scoreboard error that arose from Morkel's no-ball when he had 44 led to Stokes twice acknowledging his fifty, the second time accompanied by a sheepish grin.

England cracked on even after Stokes fell. With Moeen contributing a number of flowing drives at the other end, pushing his average at No. 7 towards 100, England's sixth-wicket pair added 166 unbroken during a lengthy evening session. South Africa visibly seemed to flag as 38 runs bled from seven overs against the second new ball, with Root closing in on a double-century.

Root had gained his first slice of luck by winning the toss on a pristine morning, and so it continued. His second scoring shot was an uppercut over the slips, suggesting his attacking instincts would remain untempered, before an attempted hook off Rabada cleared fine leg, where the substitute fielder Aiden Markram was standing in from the rope and the ball bounced behind him for four, and then a thick-edged drive at the same bowler hit the fingertips of JP Duminy in the gully. Authorities as diverse as Napoleon and Richie Benaud have noted the importance of a good leader being lucky.

His decision to move back down to No. 4 (where his average is almost ten points higher) was immediately justified, though Gary Ballance's return to Test cricket at first drop was less successful. Although Ballance struck a couple of attractive cover drives for four, South Africa's judicious use of the short ball ensured he remained camped in the crease, which was to be his undoing when struck in front by a delivery from Morkel that nipped into him. A burned review added to England's sense of waste.

England's Test summer had been launched amid nervous excitement and the clatter of early wickets, as South Africa immediately set about demonstrating why they are such indomitable tourists in this format. Philander removed both openers in his first spell, then switched to the Nursery End to trap Jonny Bairstow lbw shortly before lunch - Bairstow chose not to turn to the DRS, which was England's first good review of the morning.

The pitch, which had been cut first thing but retained a green tinge, demonstrated encouraging pace and carry from the start. "If there's any moisture in the pitch, it's going to be in this session," Dean Elgar, South Africa's stand-in captain, had suggested at the toss. That appeared a shrewd assessment, and there was also some turn on show - notably when Root walked past the delivery from Maharaj - but errors in the field took the shine off South Africa's early optimism.

It was 1983 the last time an English Test summer began as late as July but Lord's was creaking into life as Root walked to the middle in his blazer to meet his obligations as England's 80th Test captain, after a five-month wait. His predecessor, Alastair Cook, took his place back in the ranks but did not last long in his first Test innings without having to contend with the burden of captaincy. The first ball of Philander's second over was by no means his most probing, a touch short and wide, but it drew Cook into an uncharacteristic fiddle off the back foot that sent a thin edge to the keeper.

Philander claimed a five-wicket haul on his previous Test appearance on the ground, five years ago, and soon had his second this time around - though it owed more than a little to the (mis)judgment of both Keaton Jennings and umpire S Ravi. Philander rapped Jennings squarely on the pad, having straightened the ball off the seam, and Ravi raised his finger; Jennings then elected not to review after consulting with Ballance. Both decisions were proven to be erroneous, with Hawk-Eye suggesting the ball pitched fractionally outside leg and would have missed leg stump.

It wasn't the most auspicious of starts but, not for the first time, Root was working to his own script.