9th minute, row 5: at the blink of an eye: 5 in c2, 1 in c5, 7 in c8 and 2 in c9 ! Once you got it, as you knew, there is now a 2 in r6c2 and hence, r4c6; now in block 5 the 5 is forced into the lower row, and hence, in block 6 col 7: 5 up and 9 down, and hence 9 in r4c5. The rest goes without difficulty. Nice enjoyable puzzle.
9th minute, row 5: at the blink of an eye: 5 in c2, 1 in c5, 7 in c8 and 2 in c9 ! Once you got it, as you knew, there is now a 2 in r6c2 and hence, r4c6; now in block 5 the 5 is forced into the lower row, and hence, in block 6 col 7: 5 up and 9 down, and hence 9 in r4c5. The rest goes without difficulty. Nice enjoyable puzzle.