Left-hander Lumb, whose last three innings in the Royal London One-Day Cup earlier this month have been 105, 133 and 184, reached stumps on 23 not out as Nottinghamshire replied with 82 for 2 to Surrey’s first innings 323.
Notts lost both their openers, Jake Libby and Steven Mullaney, in 27 overs’ batting after quickly taking the last two Surrey wickets – Gareth Batty for 28 and Stuart Meaker for 6 – when the home side resumed on 299 for 8.
Libby was leg-before for 10 to Ravi Rampaul in the eighth over and Mullaney had batted solidly for 34 from 56 balls, hitting five fours, when he was beaten and bowled by Zafar Ansari’s left arm spin.
But Nottinghamshire will be happy enough to get through to the close with just two wickets down, as Lumb was joined by Brendan Taylor, who is unbeaten on 13, in seeing out the final overs in warm sunshine.
How different the ground looked earlier in the day, though, with heavy morning rain leaving big puddles on grass and groundsheets, and when prospects of seeing any cricket looked bleak.
Indeed, play was only able to get under way as early as 4.15pm thanks to a herculean effort from the Oval groundstaff, who spent most of the afternoon mopping up a saturated outfield after the considerable effort of hauling off the huge covers spread right across the arena.
There were a maximum of 36 overs scheduled for the session, but two of those overs were lost for change of innings after Batty and Meaker had secured a third batting bonus point for Surrey before falling in quick succession.
Batty hit a six and three fours in a punchy 32-ball innings, after resuming on 11, but Jake Ball had him caught at the wicket to finish with 4 for 85 while Meaker, on 6, chipped a return catch tamely to left arm spinner Samit Patel.