Italy made an underwhelming return to action after triumph at Euro 2020 on Thursday as the Azzurri only managed a 1-1 draw with Bulgaria in a low-key 2022 World Cup qualifier.

Some 14,000 fans showed up for the Group C clash at the half-capacity Stadio Artemio Franchi in Florence to welcome back the footballing heroes of a heady sporting summer for Italians, who also witnessed unprecedented track and field results at the Tokyo Olympics.

But after Federico Chiesa gave Roberto Mancini's side a deserved 16th-minute lead Atanas Iliev levelled just before the break to earn a point for the away team, who are ranked 75th in the world but were resolute and had goalkeeper Georgi Georgiev in inspired form when Italy did break through their tight defence.

It was not the night the fans were expecting when a starting XI with only two changes from the penalty shootout win over England at Wembley in July walked out to warm applause.

"We needed to be more clinical," Mancini, whose side have now equalled Spain and Brazil's record unbeaten runs of 35 matches, told broadcaster RAI.

"It was one of those games where we could have played for another half an hour and not scored.

"They defended well and we conceded with their one counter-attack. That's football.

"We should have been more clinical. We gave our all to win this game. We have an important game on Sunday and we must win."

Italy still lead the group, four points ahead of Switzerland, who did not play on Thursday and host the European champions in Basel on Sunday.

Only the side that tops the group will earn automatic qualification for the World Cup.

Bulgaria sit fourth on two points, eight behind Italy, knowing they still have very little chance of making it to Qatar in November next year.

"It's a shame because we wanted to celebrate the victory of July 11 with a win in front of our fans, but we'll take the point and look towards Sunday," said Leonardo Bonucci.

The fans showed their enthusiasm for the national team in the build-up to the match, lining the streets to cheer the team bus as it arrived at the ground.

They then chanted "we are the champions of Europe" as the teams prepared to kick off. They were initially treated to a match which was one-way traffic.

Chiesa gave the fans more reason to cheer when his driving run and exchange of passes with Ciro Immobile was followed by a drilled left-foot shot which gave Georgiev no chance.

Italy continued to press a Bulgaria side which had failed to win any of its previous six matches under coach Yasen Petrov, who took over the reins in January, but the home team failed to create much more.

Iliev, who plays in Italy for Serie B side Ascoli, stunned the crowd five minutes before half-time when he was gifted the chance to roll home the leveller following a deep run and low cross from Kiril Despodov.

Chiesa continued to cause problems down the right, having another good chance saved in the 62nd minute after being put through by Marco Verratti, but Bulgaria held firm as the crowd quietened in the face of an uninspiring display against a team who missed the Euro and haven't qualified for the World Cup since 1998.