Nothing could split the sides on the final day as a late charge from Middlesex sparked life into the evening and saw the contest go down to the final delivery.
Robson struck 126 not out for the hosts, sharing a fourth-wicket stand of exactly 150 with John Simpson to boost the home side’s chances of chasing down 323.
Middlesex needed 10 from the final over, bowled by Tom Taylor – and three from the last ball – but Robson could only steer it to mid-on and scrambled back for two, meaning the scores finished level.
Northamptonshire’s players took to the field wearing black armbands as a mark of respect for county stalwart Tony Kingston, who passed away on Wednesday at the age of 83, having served as their scorer for 32 years up to last season.
Surprisingly, the visitors – who were 372 for seven overnight – opted to continue batting, but extended their innings by just 11 deliveries as the last three wickets tumbled for the addition of eight more runs.
Tom Helm collected two in three deliveries to finish with three for 75, while Emilio Gay was last man out for 89, sent back attempting to snatch an ambitious single and failing to beat the throw to the bowler’s end.
Stephen Eskinazi opened the batting after falling down the order in the first innings but a recurrence of the finger injury he sustained while fielding on the first day forced him to retire just two overs into the chase.
With a number of deliveries keeping low and a track slowing up, the batting side found it hard to gain traction and they were pegged back even further when Ben Sanderson’s consistent opening spell yielded wickets in successive balls.
Mark Stoneman was first to depart, trapped in front with Pieter Malan’s off stump being uprooted the following ball.
Middlesex might have been three down soon afterwards when Max Holden drove a ball to square leg and non-striker Robson eventually aborted his bid for a single halfway down the pitch, but Sam Whiteman’s throw whistled just over the stumps.
Holden began brightly after lunch, cutting Sanderson for two boundaries and looked nicely set, contributing 37 to a partnership of 63 with Robson until off-spinner Rob Keogh castled him with a ball that drifted to leg stump, turned and clipped the off stump bail.
Keogh bowled tidily throughout an initial 11-over stint, although Simpson drove him off the back foot for four to raise the Seaxes’ total beyond three figures as he and Robson kept the scoreboard ticking along.
Robson inched towards his second half-century of the season by steering Tom Taylor for three, but the required rate had already drifted above five an over by the time Middlesex reached tea at 147 for three.
The first seven overs after the interval brought just a single boundary and the Seaxes were still struggling to accelerate when the partnership finally came to an end, with Luke Procter keeping his balance in front of the rope at long off to take the catch that removed Simpson for 75.
Procter also dismissed Ryan Higgins, who miscued to midwicket, but Roland-Jones launched a feisty assault with 34 from just 18 deliveries, including three sixes, to steer his side within 40 of the target.
Josh de Caires was lucky to survive a straight looking LBW appeal and make his way to an unbeaten 17, but Sanderson conceded only four from the penultimate over and that proved crucial as Northamptonshire did enough to deny their rivals victory.