This longitudinal study investigates the shifting roles of phonological awareness (PA) and morpho-lexical knowledge in Hebrew word reading fluency from kindergarten to Grade 4. The research addresses the developmental question regarding the relative importance of morphology versus phonology among beginning and more advanced readers. 440 Hebrew-speaking children were assessed on measures of PA and morpho-lexical knowledge in kindergarten. Reading abilities were subsequently evaluated in Grades 1 and 4, focusing on both pointed (fully voweled) and unpointed (partly voweled) Hebrew scripts. A "seesaw" effect was observed: In Grade 1, PA was a much stronger predictor of word reading fluency than morpho-lexical knowledge. However, by Grade 4, PA's contribution dropped dramatically, while morpho-lexical knowledge emerged as a stronger predictor for both pointed and unpointed Hebrew scripts. Notably, morpho-lexical knowledge showed a particularly strong influence on unpointed word reading fluency in Grade 4. These findings support the hypothesis that morpho-lexical knowledge replaces phonological awareness as the key predictor of word reading fluency by Grade 4 in Hebrew. The study extends previous research by demonstrating that explicit morpho-lexical knowledge contributes more to reading the opaque unpointed script than the transparent pointed script. This research provides insights into the developmental trajectory of reading skills in Hebrew and highlights the importance of morphological awareness in post-initial stages of reading acquisition, particularly for opaque orthographies.