Joe Ledley guaranteed Cardiff's spot in the Coca-Cola Championship play-offs with the only goal of the game against QPR.
Last season's dramatic collapse was still fresh in Cardiff memories after they picked up one point from their last four games to miss out on the play-offs by a single goal.
But there are no such worries this time round with Dave Jones' side assured of a shot at Wembley and the Premier League with two games to spare.
Ledley has suffered an injury-hit season and only recently returned to action following a double hip operation.
But he picked the perfect time to score his third goal of the campaign, tucking away Mark Kennedy's cross with 10 minutes remaining.
Rangers sat fourth in October with ambitions of being in the promotion shake-up themselves, but after another traumatic season in west London they only recently climbed clear of relegation trouble.
Adel Taarabt, the on-loan Tottenham midfielder, provided the main threat as the hosts dominated the opening period.
In the first 30 seconds he raced at the Cardiff backline before firing inches wide and the Moroccan came even closer in the 18th minute when his shot from the edge of the area came back off the inside of the post with City goalkeeper David Marshall beaten.
Taarabt then tormented City defender Kennedy down the right before delivering a low cross which Jay Simpson, Tamas Priskin and Hogan Ephraim all somehow missed.
Cardiff's best chance of a pedestrian first-half display fell to Stephen McPhail, who fired high and wide from the edge of the area.
Cardiff blew a golden chance to take the lead in the 54th minute when Rangers goalkeeper Radek Cerny spilled Ross McCormack's free-kick at the feet of Anthony Gerrard, but the defender could not find the finish and Kaspars Gorkss was able to clear.
But they made the breakthrough in the 80th minute, Kennedy overlapping down the left and standing the ball up for Ledley to arrive at the far post and bundle home in front of a joyous away following.
Kelvin Etuhu could have doubled the lead but was denied by Cerny, while at the other end Rangers substitute Lee Cook had the opportunity to spoil the party with a late volley but Marshall pulled off a fine save to secure the win.
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