Belgium joins Brazil, Iran, Japan, Mexico and host Russian Federation in guaranteeing a place at next year's finals.
Breathing down their necks now are Sweden, who had earlier thrashed Belarus 4-0, while Holland kept their hopes of automatic qualification alive with a 3-1 win over Bulgaria.
"What is most fun in football is when you win matches that take place under such conditions". I had asked the team to win at all costs.
Lukaku who has been in sparkling form this season for Manchester United scored the victor for Belgium in the 74th minutes after being set up by Kevin de Bruyne.
Robben scored the second in the 67th minute for his dominant side, finishing the excellent Blind's cross from six yards out after a superb team move which he started off. "We must try to find a solution in Russian Federation against teams that are so strong".
Dries Mertens opened the scoring after 15 minutes before Thomas Munier doubled the home's side lead three minutes later.
"Of course, the pitch is not the only reason we kept the ball too much instead of playing around".
Hungary had Tamas Priskin given a straight red card for elbowing Portugal defender Pepe in the 30th minute, one of several nasty challenges in a rough encounter.
That result was the third consecutive draw for the Greeks, who look strong defensively but have not managed to find the back of the net in their last two games.