Wales looked to be running out of time against Bulgaria before full back Williams, who made his debut against Finland on Thursday, headed home at the back post.

The Welsh top the second level Group B4 on six points with Finland second on three after winning 1-0 against the Republic of Ireland, who are on one point along with Bulgaria.

Russia maintained their winning start in B3 with a 3-2 triumph in Hungary building on an opening success over Serbia, who later look to bounce back against Turkey.

Slovenia took control of C3 with a 1-0 win over Moldova though Kosovo or Greece could join them on four points when they meet later.

And in bottom tier D1 the Faroe Islands built on their opening win over Malta by winning 1-0 away to Andorra. Malta welcome Latvia in the other game.

In the top-tier Group A4 Spain host Ukraine later after opening their campaign with a Thursday draw in Germany, who now travel to Switzerland. Ukraine top the group having defeated Switzerland already.

Bulgaria seemed to have done enough to secure a share of the spoils before Jonny Williams crossed for Neco Williams and the 19-year-old ensured Wales of a fourth consecutive competitive win.

"To finish off the game like that and get my first goal for my country is a proud moment for me and my family," the match-winner said.

"It's all happened so quick, when you are a kid you dream of playing for your country so to get the opportunity is surreal."

Wales visit Ireland and Bulgaria in October when the Nations League resumes.

Ireland rescued a late point away to Bulgaria in their first game but Fredrik Jensen struck midway through the second half to condemn them to defeat by Finland, who next host Bulgaria.

Russia raced to a three-goal lead in Hungary through Anton Miranchuk, Magomed Ozdoev and Mario Fernandes just after the break but Roland Sallai and Nemanja Nikolic set up a tense finale.

In October Russia host Turkey and Hungary, who are second on three points before Sunday's other game.

Damjan Bohar struck the only goal in the first half against Moldova to keep Slovenia unbeaten in the competition though a tough October, with a visit to Kosovo and the return in Moldova awaits.

The Faroes are also top of their group thanks to Klaemint Olsen's deflected strike in the first half.

European governing body UEFA said it was the first time the Faroes have won consecutive competitive games since 1997.

They will continue their campaign with a home double-header against Latvia and Andorra next month.

Australian Associated Press