High-mass stars play a major role in the energy budget of galaxies via their radiation, wind, and supernova events, but the picture of their formation is incomplete. Hub-filament system (HFS), often observed to transfer mass to form massive stars, can serve as a laboratory to study the detailed process of mass transfer and fragmentation. We present hybrid ALMA Band-3/7 observations towards "the Heart" of a massive HFS called SDC335, to investigate its fragmentation and accretion. At a resolution of 0.03 pc, 3 mm continuum emission resolves two massive cores MM1 and MM2, with 383 and 74 solar mass. With a resolution down to 0.01 pc, 0.87 mm continuum emission shows MM1 further fragments into six condensations and the H2CS lines provide accurate temperature estimation. The relation between separation and mass of condensations at a scale of 0.03 pc favors turbulent Jeans fragmentation where the turbulence is scale-free rather than scale-dependent. We use the H13CO+ (1-0) to resolve the complex gas motion inside "the Heart". We identify four major gas streams connected to large-scale filaments, inheriting from the anti-clockwise spiral pattern. Along these streams, gas feed the central massive core MM1 with an infall rate of 2.40(0.78)E-3 solar mass per year, numerically consistent with the accretion rate derived from the clump-scale spherical infall model and the core-scale outflows. The consistency suggests a continuous, near steady-state, and efficient accretion from global collapse, therefore ensuring core feeding. Our comprehensive study of SDC335 showcases the detailed gas kinematics in a prototypical massive infalling clump, and calls for further systematic and statistical studies in a large sample.