Brilliant Rashford and Foden justify Southgate's rare reshuffle against Wales
Raheem Sterling (27) and Southgate's beloved Bukayo Saka (21) had appeared undroppable in the last couple of years but, in the wake of the shockingly toothless display against the United States, Southgate finally showed he could take decisive action for the Wales match.
Both forwards were benched and in came Rashford and, satisfying the public clamour at home, Foden.
Rashford struggled with his passing in the first half, though he was far from alone there as England totally controlled play but created little.
Within five minutes of the restart, however, he broke the deadlock with a rarity at this World Cup - a goal direct from a free kick - as his fierce, dipping effort flew beyond goalkeeper Danny Ward.
Throughout the first half Foden had been faithfully making the sort of runs up the right wing that so often create space and spark chances at Manchester City, but his England teammates, perhaps still unused to seeing him alongside them, were on a different wavelength and rarely picked him out.
He switched to the left in the second half and a minute after the opener was finally found with a skidding low cross by Harry Kane that he gleefully sidefooted in, beaming with joy even as the ball was arriving as his feet secure in the knowledge that he was about to score at a World Cup.
Such was Rashford’s growing confidence that he then did something he almost never does - cut inside and shot with his left foot - and Danny Ward was as surprised as the England fans massed behind the goal as he allowed the ball to go between his legs for the third goal.
Rashford has not had the greatest last year or so and perhaps only a late surge of form for Manchester United earned his place in the squad for Qatar.
It is probably no surprise that he has never really felt a settled part of Southgate’s plans as Tuesday represented only his second start in his 15 appearances in four World Cup and European Championship tournaments.
He came off the bench five times at Euro 2020 and until Qatar, his last contribution was to send his penalty against a post in the final shootout defeat to Italy.
"Moments like this, this is what I play football for - the biggest moments, the best moments," he said after being named man of the match on Tuesday.
"I'm happy we're going through to the next round of the tournament because I have massive ambitions for this team and I think we can play even better than we did today," he added looking ahead to Sunday's last-16 clash with Senegal.
Southgate was also full of praise for the striker.
"It's been a challenge for him," said Southgate after handing Rashford his first start since June last year.
"I went and saw him in the summer and had a long chat, he had some clear ideas on what he felt he needed to do and you can see with his club, that has shown itself with us. We have a different player to the Euros.
"It's great for him and great for us."
With qualification virtually assured, Southgate also did something he has rarely done - taking off Kane and Declan Rice off after 57 minutes to give them a decent rest instead of his usual approach of running his key striker into the ground.