The sun burst through after lunch and that adage about looking up to the sky, rather than down at the pitch, rang true as Smith and Webster patiently steadied the ship for Australia.
Since his last Test at Lord's during the 2023 Ashes – when he made 110 - Smith has endured a slightly fallow period by his standards.
Against India at the Gabba last December he ended a run of 24 innings without a Test century, and since then has reeled off three more.
He looked a good bet here: holding his focus until a scoring opportunity presented itself then expertly finding the gaps to the boundary, with that familiar idiosyncratic strokeplay, to reach a half-century.
No overseas player has more than the 591 Test runs, at an average of 59.10, Smith has scored at Lord's.
His kryptonite at the venue is spin – against pace bowling Smith averages 112.75 at the home of cricket, but that figure plummets to 23.33 against the tweakers.
Still, it felt more like hubris which brought about Smith's downfall when he looked almost certain to go on to three figures.
Instead he became Markram's fourth Test wicket when he slashed the part-time off-spinner to Jansen at slip, who juggled it before clinging on.
That cast Webster, who had earlier had a let-off when Bavuma declined to review a plumb lbw when on eight, as the man to perform the rescue act.
He played diligently until a slightly lazy waft off Rabada gave Bedingham a second grab in the slips. Given what would come later in the day, his and Smith's contribution could prove decisive.
Australia's uncharacteristically tail failed to wag with Rabada providing the coup de grace to Australia's innings when he pinned back Starc's leg stump to claim his fifth wicket.
However, Starc wrestled back a sizable portion of the momentum with two later wickets before Cummins and Hazlewood both struck.
South Africa found runs difficult to come by, with Rickleton the only player into double figures, leaving Bavuma and Bedingham facing a tough challenge on day two.