Wales claimed a 1-0 qualifying victory over Estonia in Tallinn on Monday to keep Belgium waiting for a place at the 2022 World Cup.
Kieffer Moore's scrappy 12th-minute goal was enough for Wales to make amends for a disappointing goalless home draw with Estonia last month.
Anything other than a Welsh win would have seen Belgium wrap up top spot in Group E, without playing on Monday, and a spot in Qatar next year.
The win keeps alive Welsh hopes for at least a play-off spot but they also still have to take on Belgium.
Belgium can still secure a finals berth when they host Estonia next month before playing Wales in the final round of matches.
The Czech Republic sit second in the group on goal difference after winning 2-0 against Belarus, but have played a game more.
The visitors started brightly, with Harry Wilson curling a free kick over the crossbar before Estonia goalkeeper Karl Hein turned away Connor Roberts's effort at full stretch.
Wales took the lead from the resulting corner, a goal-mouth scramble ending with the ball bouncing in off Moore from barely a yard out.
It was the Cardiff striker's first international goal since Euro 2020 and seventh in total for his country.
Wales dominated possession for most of the first half but struggled to create many more clear chances, with Wilson striking another free kick straight at Hein.
Wales were almost made to pay shortly after the restart, as Estonia striker Erik Sorga headed the ball over when he should have done better.
Wales appealed for a penalty when Moore tussled with home captain Marten Kuusk in the area, but a free kick was awarded against the forward, who was left with a bloody nose.
The away side started to look nervous late as Estonia exerted some pressure.
Vlasiy Sinyavskiy was denied by an excellent save from Danny Ward, who bounced back from a horrendous error in Friday's 2-2 draw against the Czech Republic with a clean sheet.