Slight left hamstring problem at start, during and after run. Basically, ran about 30 seconds per mile faster than a few days ago, but still 30 seconds per mile slower than would have done otherwise, and avoided speeding up on downhills. At time of finishing, no left cartilage problem.
Time doesn't really count as just jogging with neighbour, but kept speed very low. As at finish time, the same hamstring problem before, during and after as yesterday, but otherwise, ok, and importantly, left cartilage not playing up. 24 hours later and cartilage still not causing a problem.