England's first win against Italy on Italian soil since 1961 and a first competitive victory over them anywhere since 1977 was rightly celebrated at the final whistle.
Southgate's decision to start Kalvin Phillips despite his lack of game time for Manchester City paid off and he trusted Jack Grealish from the start - a decision many England fans demand every time the squad meets up.
Yet for all the positives and the fact that Southgate joins Alf Ramsey and Walter Winterbottom in an elite group of England managers with 50 wins, his tactics will still be questioned.
After dominating the first half when they could have been three or four goals ahead, England were unrecognisable after the break as they allowed a less-than-vintage Italian side to take command as Southgate's players inexplicably backed off.
From the moment Mateo Retegui struck for the hosts in the 56th minute it was one-way traffic but England, despite having Luke Shaw sent off late on, managed to hold out for a win that makes them favourites to win Group C.
"We showed two sides without a doubt," Southgate said. "We had great control from the back in the first half and when we broke through that first line of pressure we looked dangerous.
"Frankly, we should have had the game buried. It should have been 3-0 at halftime.
"But if you start any half of football the way we started the second, you're going to be in trouble and we concede a really poor goal. Several errors in the lead-up to it.
"Then of course, the emotion of the whole evening changes."
It was all very similar to the Euro 2020 final when England scored first at Wembley before handing the initiative to Roberto Mancini's side and losing on penalties.
This time England prevailed and Southgate will point to the fact that Italy lost a Euro qualifier for the first time in 41 matches.
Yet his detractors will seize on the second-half display as a reason to doubt whether he can deliver the silverware that has proved agonisingly out of reach since he took over in 2016.
Southgate, however, said his players had shown they could "grind and dig in" when the going got tough.
"Given our record here, it's a massive result," he said. "But, equally, we would prefer more of the first half than the second."