Faf du Plessis warned South Africa cannot afford to suffer a "mental hangover" as they try and get back into the series against England after watching the tourists slump to a crushing defeat in the first Test.
Du Plessis ruled himself out of the opening match of the series following the birth of his first child, but was at Lord's on Sunday to see England wrap up a 211-run win inside four days.
Man-of-the-match Moeen Ali claimed his first 10-wicket Test haul as the Proteas, led by stand-in skipper Dean Elgar, folded to 119 all out after bowling Joe Root's side out for 233 on a day in which 19 wickets fell.
Du Plessis said South Africa must learn lessons from such an emphatic loss as he prepares to resume his duties in the second game of the four-match series, which starts at Trent Bridge on Friday.
The skipper said: "This Test match was just a lot of errors, a lot of basic mistakes as a team and that will cost you if you're playing against a strong team like England.
"So for me it's just a pretty straightforward thing to focus on this week, get your basics right.
"Do things consistently better for longer and you'll have moments in the game where you put pressure on the opposition and times where they will put pressure on you and you just make sure you run with it for a while and wait for your turn to put it back on them.
"It's really important after this Test match that you don't almost fall into the mental hangover of the tour that we've had so far, so that will be one of my most important jobs and the senior players this week.
"Make sure we stay well clear of that and focus on the next Test match."