Bacteria and their viruses, known as bacteriophages, are engaged in an evolutionary battle that drives the development of strategies each use to outcompete the other. Successful infection requires immediate evasion of antiphage defences and takeover of host machinery, nutrients and energy. Here, I have defined a genomic region in P. aeruginosa phages that contains genes responsible for orchestrating different early host takeover strategies. Accordingly, it is named the Eht region for ‘early host takeover’. The Eht region is expressed early and varies in length, sometimes comprising up to 25% of the genome. It contains diverse combinations of genes that are relatively unique to this region, suggesting phages ‘pick and choose’ them from a larger pool. It is predominantly made up of uncharacterized genes but is enriched for genes involved in early steps of phage infection including gene expression, genome replication and recombination. Investigation of seven Eht genes revealed five proteins, four hypothetical and one putative recombination protein, that influence infection dynamics in a manner that can profoundly influence the success of the phage in competitive environments. Two of the hypothetical proteins, named Eht1 and Eht2, do this by collaborating to reprogram P. aeruginosa metabolism and signaling. As phages employ tactics for early host takeover, bacteria must counteract with antiphage defences. Given their pivotal role in the initial stages of infection, early host takeover proteins are prime targets for these defences to stem phage intrusion as swiftly as possible. In line with this, our investigation uncovered a potentially novel antiphage defence mechanism that detects a conserved component of the Eht region, a putative phage-encoded helicase. A deeper understanding of the interplay between early host takeover strategies and antiphage defences promises valuable insights into therapeutic targets in bacteria, applications of phages including their potential as an antibiotic alternative, and cellular processes that can be adapted for innovative molecular tools.