Chris Coleman's men arrived in Brussels a point clear of Israel at the top of Group B and, as expected, had to fight hard to maintain a three-point advantage over Belgium.
Gareth Bale twice went close from set-pieces, as well as firing narrowly wide midway through the second half, but this was a match in which Wales' character and defensive qualities were put to the test.
The visitors had to withstand periods of sustained pressure, with Eden Hazard pulling the strings for much of the encounter.
The Chelsea star had an effort saved by Wayne Hennessey early on, before Nacer Chadli was also thwarted by the Wales goalkeeper.
Nicolas Lombaerts struck the post before half-time and the second period proved even more frustrating for Marc Wilmots' side, as Wales showed no sign of giving in.
Bale provided a crucial intervention at the death, blocking a Christian Benteke header on the line to ensure Wales earned a point and followed up their 1-1 draw in a World Cup qualifier at the same venue last October.
Jan Vertonghen captained Belgium in the absence of injured skipper Vincent Kompany, while Bale led the line for Wales with Coleman desperately short of out-and-out strikers.
The visitors started brightly, but James Chester had to be alert at the back to deny Marouane Fellaini a chance to head Belgium in front from a dangerous Hazard cross.
Bale registered the game's first shot on target 14 minutes in when he drew a diving save from Thibaut Courtois with a swerving free-kick from 25 yards, before Hazard's low drive at the other end was collected by Hennessey at the second attempt.
A delightful Divock Origi flick sent Chadli clean through on goal in the 23rd minute, but Hennessey did well to close down the Tottenham attacker and thwart the move.
Wales came under increasing pressure as the half progressed and Lombaerts sent a curling strike against the left-hand upright – Origi sending the rebound wide of the other post.
Hal Robson-Kanu was lucky to escape punishment after a coming together with Anthony Vanden Borre in the closing stages of the first half, but Wales held firm to go in level at the break.
Wales had struggled to provide Bale with any service during the opening 45 minutes, appearing unwilling to compromise their defensive solidity to show some adventure in attack.
However, the Real Madrid forward carved out an opportunity of his own shortly before the hour mark – driving across the face of goal after splitting two defenders.
The chance prompted a spell of Welsh pressure, and Bale stung the palms of Courtois with another well-struck free-kick.
Belgium pushed hard for a winner in the last 10 minutes, but Robson-Kanu almost caught the home defence napping as he forced Courtois into another save.
Substitute Dries Mertens was left requiring lengthy medical attention following a nasty clash of heads with George Williams as the match approached its conclusion – the Napoli attacker playing no further part.
The incident prompted six minutes of injury time, but Belgium – 30 places higher than Wales in the world rankings - were unable to avoid dropping points for a second time in three qualifying matches, with Bale making the vital late block from Benteke.
