The Durham all-rounder scored 188 not out to help his side avoid the follow on, before going on to amass 447, a deficit of only 87. He then claimed the only wicket to fall as Notts reached stumps on 104 for one in their second innings.
Borthwick batted for more than six hours, scoring his runs from 279 balls, with 28 fours and a six, to ensure his side collected maximum batting points.
Jackson Bird failed to add to his wicket tally from the previous day and ended with bowling figures of four for 109, Harry Gurney took three for 125 and Brett Hutton finished with two for 70.
Notts struck right at the start of the day’s play as Paul Collingwood departed for 40, edging Gurney to Steven Mullaney at second slip.
Ryan Pringle chipped in with 34 in a stand of 84 and then James Weighell made 22 before being given out lbw.
Support for Borthwick then came from an improbable source. Brydon Carse had left the field on the first day with a foot injury and wasn’t expected to bat. He emerged with Keaton Jennings as his runner and proceeded to hammer a career best of 47 runs from 66 balls, hitting eight fours and a monstrously big six off Samit Patel’s bowling.
Borthwick had brought up his fifth century of 2016 from 158 balls, with 18 fours, adding his third for Durham to the two he scored in the spring for Wellington.
His 150 arrived from 225 deliveries and he then pulled Hutton for his only maximum. Thoughts of reaching the second double hundred of his career were quickly dashed as Chris Rushworth edged behind for two and Graham Onions was bowled for four.
Borthwick had taken five wickets in Nottinghamshire’s first innings and it took him only two deliveries to make inroads when they batted again, trapping Mullaney lbw for 43.
Jake Libby and Greg Smith remained together until the close, by which time Notts had built an overall advantage of 191.
Both sides have taken seven bonus points from the contest so far and will be hoping an indifferent weather forecast doesn’t prevent them from pressing for a win on the final day.