Multi-hop　data　collection　in　wireless　sensor　networks　(WSNs)　is　a　challenge　issue　due　to　the　limited　energy　resource　and　transmission　range　of　wireless　sensors.　The　hybrid　clustering　and　routing　(HCR)　strategy　has　provided　an　effective　solution,　which　can　generate　a　connected　and　efficient　cluster-based　topology　for　multi-hop　data　collection　in　WSNs.　However,　it　suffers　from　imbalanced　energy　consumption,　which　results　in　the　poor　performance　of　the　network　lifetime.　In　this　paper,　we　evaluate　the　energy　consumption　of　HCR　and　discover　an　important　result:　the　imbalanced　energy　consumption　generally　appears　in　gradient　k　=　1,　i.e.,　the　nodes　that　can　communicate　with　the　sink　directly.　Based　on　this　observation,　we　propose　a　new　protocol　called　HCR-1,　which　includes　the　adaptive　relay　selection　and　tunable　cost　functions　to　balance　the　energy　consumption.　The　guideline　of　setting　the　parameters　in　HCR-1　is　provided　based　on　simulations.　The　analytical　and　numerical　results　prove　that,　with　minor　modification　of　the　topology　in　gradient　k　=　1,　the　HCR-1　protocol　effectively　balances　the　energy　consumption　and　prolongs　the　network　lifetime.　©　2015　by　the　authors;　licensee　MDPI,　Basel,　Switzerland.