England have won their Euros opener against Croatia at Wembley.
Raheem Sterling gave the home team the lead after 57 minutes with his first major tournament goal.
The Manchester City player was slipped in by Kalvin Phillips and he coolly fired a first-time effort in from 12 yards.
Southgate's side saw out the victory, their first win in an opening game of a European Championship, relatively untroubled to make the perfect start to Group D.
Jude Bellingham, who turns 18 on June 29, became the youngest player ever to appear at the European Championship after replacing Harry Kane with eight minutes left.
England shone during an encouraging opening 20 minutes, only for Croatia to settle and take the sting out of a sharp attack that continued to underwhelm early in second half.
The Three Lions had never previously won their opening game at a European Championship, but Phillips and Sterling would soon end that run.
In the 57th minute, Kalvin Phillips cut inside and smartly put through Sterling to smash home his first tournament goal as fans celebrated a Three Lions strike at Wembley for the first time since November 2019.
It proved the winner at the end of a week to remember for the 26-year-old, who was made an MBE for his work for services to racial equality in sport in the 2021 Queen’s Birthday Honours.
Some England fans once again defied calls not to boo the players as they took the knee before kick-off.
Three Lions boss Gareth Southgate, the Football Association and Prime Minister Boris Johnson all urged supporters not to boo the anti-racism stance.
But those requests fell on some deaf ears, with an audible round of jeers from some of the expected 22,500 crowd – although cheers from the vast majority soon drowned them out.
The Croatia national anthem was also booed and the reaction followed on from jeers at the two warm-up games played at Middlesbrough’s Riverside Stadium.
Sunday's result was an ideal start to Group D at a difficult time for England, with Southgate pleased by his side’s display against wily opposition.
"It feels great to have been able to send the fans home happy and to have fans up and down the country happy,” the England manager said. “That’s very special.
“In terms of the game, I was really pleased with the way we settled so quickly.
“Some young players, some inexperienced international players, a big occasion – not only a tough opponent but a big occasion, a sweltering hot day."
England will return to Wembley to take on Scotland on Friday 18.