Ghana has qualified for four of the last five World Cups — only missing out in Russia in 2018 — and reached the quarterfinals in South Africa in 2010.
The Black Stars were a big favorite at home against Madagascar but manager Chris Hughton's team struggled to breach the visitors' organized defense in Kumasi, Ghana’s second largest city.
Williams finally broke the deadlock with a powerful header after the Spain-born Athletic Bilbao forward had an earlier goal disallowed for offside.
The two teams observed a moment of silence in memory of former Ghana and Levante striker Raphael Dwamena, who collapsed and died on the field last Saturday during an Albanian league game.
Also Friday, Leicester forward Patson Daka scored twice as Zambia defeated Republic of Congo 4-2 at home. Lameck Banda and Fashion Sakala got the other goals for the host in Ndola. Silvère Ganvoula M’Boussy and Mons Bassouamina scored for the Congolese.
Malawi snatched a 1-0 win away to Liberia in Monrovia through a 78th-minute goal by teenager Chifundo Mphasi.
Libya won 1-0 away against Eswatini in a match played in South Africa, Comoros beat Central African Republic 4-2 at home and Guinea edged Uganda 2-1 in Morocco.
Nine teams from Africa will qualify directly for the 48-team 2026 World Cup in the United States, Mexico and Canada. A 10th team could make the field through the playoffs.