Now the only two sides who can claim the group's single guaranteed qualifying spot head into their closing fixtures on Monday with it all still to play for.
Roberto Mancini's side travel to Northern Ireland while Switzerland, who recovered some pride at the Stadio Olimpico after being thumped at the same ground by Italy at Euro 2020, host Bulgaria.
Italy now have to match Switzerland's result to ensure a place in the World Cup, assuming that Switzerland fail to beat Bulgaria heavily enough to finish the group with the superior goal difference.
That leaves Italy facing the spectre of the play-offs, where in 2017 they failed to qualify for the World Cup for the first time in six decades following a miserable aggregate defeat to Sweden.
"He (Jorginho) is one of our penalty takers and he wanted to take it so it's logical that he took the penalty," Mancini told broadcaster RAI.
"We played well in the second half after a difficult first half, the only thing missing was the goal. We start the final day with an advantage, which is not nothing. If we win."
Widmer stunned the just under 50,000 crowd at the Stadio Olimpico with 10 minutes on the clock, meeting Noah Okafor's pull-back with a thumping strike that whizzed past Gianluigi Donnarumma and into the top corner.
The hosts were rocked and Switzerland could easily have been two ahead shortly after, with a goalmouth scramble being hastily cleared away and the bright Okafor then fizzing a low shot just past the upright.
Yann Sommer, the hero of the Swiss' penalty shootout win over France at Euro 2020, pulled off a super save on Nicolo Barella in the 22nd minute after Jorginho's shot fell to the Inter Milan midfielder.
However he could do nothing about the leveller 13 minutes later, as he failed to get a hand to Lorenzo's Insigne's deep free-kick before it reached Di Lorenzo's head and sailed into the net.
Italy's tails were up but they failed to create much going forward, being largely restricted to long shots and well shut down when they did managed to penetrate the Swiss penalty area.
Federico Chiesa thought he had wasted Italy's last chance when he shot a presentable opportunity wildly over the bar with two minutes remaining.
But the crowd breathed a huge sigh of relief when referee Anthony Taylor, who had previously waved away appeals for a penalty for what the home side thought was a foul by Ulisses Garcia on Berardi, then pointed to the spot after watching the incident on the pitch-side monitor.
Expecting to celebrate the goal which would have almost guaranteed a return to football's biggest stage, the home crowd stood in disbelief as Jorginho put his penalty onto the Stadio Olimpico running track and left Italy wondering if they were going to another play-off showdown for the World Cup.