The 6TiSCH working group is standardizing the low-power wireless protocol stack for the Industrial IoT. The default scheduling function (SF0) standardized by 6TiSCH uses simple random slot selection. This paper proposes the Low Latency Scheduling Function (LLSF), a new scheduling function which daisy-chains timeslots rather than picking them randomly. We implement LLSF in OpenWSN and evaluate its performance experimentally. LLSF yields 82.8% lower end-to-end latency on a 5-hop path than SF0, at no extra costs.