Gee, the title sure is sensationalist. Nothing has been 'won' yet. The actual percentage here don't matter, the system works using two rounds in each circonscription (subdiv of France which can elect 1 MP). What really matters now is who will call to vote for who. The NFP (Left Alliance) leaders said no vote for Far Right, and Macron (in spite of how much he shat on the left) called for a 'grand coalition against the RN' (RN being Far Right here).
And I'll repeat it as many times as it takes 34% IS FAR FROM 50% (The RN is unlikely to find allies, as all the traitors of the trad right wing party have already gone to them)
Edit: forgot to mention that not all votes have been counted yet, the big cities finishing up later, which will likely drive the NFP's score up and RN's down.