The Kings lost in Dallas for the seventh straight time.
Los Angeles' only goal came from Tom Preissing. The Kings have lost their last two games by a combined score of 10-4.
Ribeiro scored on a tip-in with 8:08 left in the opening period and Morrow scored the first of Dallas' three second-period goals on the power play 2:40 into the stanza.
The four-point game was the third of Ribeiro's career.
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