Consecutive training on different movement sequences performed with the same motor effectors often leads to retroactive interference - obstructing memory for the initially trained sequence but not for the second. However, in the context of hippocampal-system dependent memories, a poor learning experience, one whose behavioral effects would soon decay, can be enhanced if temporally paired with a ‘strong’, consolidation-triggering, experience. The Synaptic Tagging and Capture hypothesis (STC) explains this paradoxical enhancement by suggesting that synapses specifically engaged in a ‘weak’ learning experience can capture and utilize plasticity-related-resources generated for a subsequent ‘strong’ learning experience. Here we tested whether such ‘paradoxical’ outcome would result in the context of motor (procedural) memory, if two movement sequences are unequally trained, consecutively. We show, in young adults (N=100), that limited practice on a novel sequence of finger-to-thumb opposition movements, led to different long-term outcomes, depending on whether and when (5-minutes/5-hours later) it was followed by extensive training on a different sequence. Only in the five-minute pairing condition, there were overnight gains for the limited-trained sequence; these were well-retained a week later. However, overnight gains for the extensively trained-sequence were compromised. We propose that the newly discovered, “paradoxical”, mnemonic interaction may reflect competition, for plasticity related cellular products, between sequence-specific synapses, within neurons in the motor circuitry engaged by both sequences; synapses engaged by practicing the limited-trained sequence “capture” plasticity-related-resources generated for the subsequent extensively-trained sequence. This suggests that STC notions may be generalized to motor behavior, specifically, procedural, non-hippocampus dependent, long-term memory.