Joe Root marked his first innings as England captain with a superb 184 not out against South Africa at Lord's on Thursday.

England were 357 for five at stumps, having collapsed to 76 for four before lunch on the first day of the opening Test of a four-match series.

But Root's 12th hundred in 54 Tests and third at Lord's justified his decision to bat first after winning the toss in what was England's first match at this level since he was appointed following Alastair Cook's resignation as skipper in February.

New vice-captain Ben Stokes made 56 and helped turn the tide in a fifth-wicket stand of 114.

Moeen Ali's 61 not out cemented the recovery as he added an unbroken 167 with Root.

Concerns had been expressed that captaincy would reduce Root's effectiveness as a batsman.

But, on this evidence, Root appears destined to follow the other members of world batting's 'big four' -- India's Virat Kohli, Australia's Steve Smith and New Zealand's Kane Williamson -- all of whose Test averages as captain of their respective countries have far outstripped their equivalent figure in 'the ranks'.

Earlier the 26-year-old Root opted to bat first after the coin fell in his favour.

But a green-tinged pitch gave South Africa's bowlers hope of early movement.

Cook had made just three when he was caught behind flat-footedly chasing a Philander ball outside off stump.

Fellow opener Keaton Jennings, born in South Africa, fell next for eight on his home debut when lbw to Philander, who bowled the Proteas to a series-clinching victory at Lord's five years ago.

The 32-year-old Philander, fit following an ankle injury sustained while playing for English county side Sussex, had now taken two wickets for three runs in eight balls to leave England 17 for two.

Root, meanwhile, was fortunate, when on five a top-edged hook off Kagiso Rabada just cleared substitute fielder Aiden Markram, who was not right back on the rope at long leg.

He had another break when on 16 an edged drive off Rabada flew through JP Duminy's hands at gully.

Meanwhile Root's Yorkshire colleagues Gary Ballance (20) and Jonny Bairstow (10) both fell cheaply.

But Stokes, who has known Root since their days as schoolboy cricket opponents, took the attack to the Proteas by driving spinner Keshav Maharaj for six.

He was 'bowled' off a Morne Morkel no-ball on 44, the fast bowler having only himself to blame for a considerable over-step.

Stokes, however, fell soon afterwards when his top-edged hook off Rababa flew straight to wicket-keeper Quinton de Kock.

Root, however, kept going and a swept three off Maharaj saw him to a 150-ball hundred, including 15 fours, after more than four hours at the crease.

His century also meant the last four England Test captains -- Andrew Strauss, Kevin Pietersen, Alastair Cook and now Root himself -- had all scored a century in their first game as skipper.

Fully in command on a pitch dried out by the sun, Root drove Maharaj for six over long-off.

Root should have been out for 149 when he charged down the pitch to Maharaj and was stumped by yards.

But replays showed that Maharaj had bowled a no-ball -- an inexcusable error for a slow bowler.

South Africa, with Dean Elgar captaining the side in the absence of Faf du Plessis, still at home following the birth of his first child, had long since gone on the defensive in the 'hope' of a wicket more than anything else.

The new ball failed to produce a breakthrough, with Root dismissively driving Rababa through the covers for four and two balls later pulling him for another boundary.

Play ended with the Proteas three short of the standard 90 overs in a day's play.

Not that Root, whose father, grandfather and young son were at Lord's, would have cared as walked off to a standing ovation.