Dave Taylor scored two tries and Willie Mason made his debut as Catalans Dragons secured their first win of the Super League season and amplified the problems facing last year's treble winners Leeds.
Richie Myler, Krisnan Inu and Tony Gigot also breached the Leeds defence in a 32-28 home win in Perpignan.
Leeds also plundered five tries but Jordan Lilley failed to convert the late scores from Ash Handley and Kallum Watkins, as the reigning Super League champions slumped to a third successive defeat at the start of this season's competition.
They sit bottom of the pile, with much improvement required to be competitive in the upper echelons this term.
The Catalans gave debuts to Mason and Jodie Broughton as they attempted to recover from their opening two defeats.
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Leeds made one change from their defeat in last weekend's World Club Challenge game against North Queensland Cowboys - Mitch Achurch replacing the suspended Mitch Garbutt.
Both sides started the game with a nervous edge, knowing the beaten side would end the weekend bottom of the table.
Catalans opened the scoring, Taylor latching on to Todd Carney's neat inside ball to score to the right of the posts in the sixth minute, with Pat Richards converting.
Leeds levelled after 22 minutes as Watkins pounced on Gigot's error in his own in-goal area to score. Lilley added the extra two points.
With five minutes remaining of the first half, Myler scored the try of the game, collecting Broughton's kick to touch down under the posts. Richards added the conversion to give the hosts a six-point-lead once again.
Leeds were awarded a penalty on the half-time hooter and Lilley narrowed the Rhinos' deficit at the interval to 12-8.
Catalans started the second half in scintillating form, scoring twice in the opening five minutes.
Inu scored a superb solo effort, dummying and stepping his way to the line from 40 metres out. Richards again converted to give the hosts a 10-point advantage.
It got better for the home side as they marched upfield without Leeds touching the ball to score again. Glenn Stewart and Carney combined to send Gigot over under the posts, and Richards converted to take the score to 24-8.
Leeds were not going to lie down and let the Dragons run riot and responded with two tries of their own.
On the hour, Taylor charged over under the posts from close range to give the home side some breathing space.
