Robson, New South Wales born but who has made seven Test appearances for England, hit 133 in an first-wicket stand of 173 with Joshua De Caires (76), while Roman Walker took 3-57 for the home team.
Landmark centuries from Keaton Jennings and Australian-South African Chris Green revived Lancashire against Derbyshire at Chesterfield.
Jennings passed 12,000 first-class runs on his way to 106 while Green celebrated his maiden red-ball hundred as Lancashire recovered from 6-132 to 367 all out.
Gloucestershire's Western Australian captain Cameron Bancroft scored a half-century, along with Zaman Akhter and the unbeaten James Bracey, as their side closed on 7-279 for seven against Glamorgan at Cardiff.
Timm van der Gugten trapped Bancroft lbw for 50 and later dismissed Akhter by the same method for 58. Mason Crane chipped in with three wickets.
Highlight of the Division One action came at Southampton where Adam Hose made a career-best 266 during a third-wicket stand of 395 with Jake Libby as bottom-of-the-table Worcestershire dominated against Hampshire.
Hose smashed 31 fours and seven sixes off 253 deliveries, while stand-in captain Libby passed 10,000 career runs on his way to an unbeaten 137.
The Pears, who have won only once all season, reached 3-463 at stumps.
Centuries from Dom Sibley and Sam Curran helped reigning champions Surrey take control against Durham.
Opener Sibley remained unbeaten on 169 and Curran contributed 108 off 124 balls in a score of 407 for three, with captain Rory Burns having registered 55 at the start of the innings at The Oval.
Dan Lawrence will resume alongside Sibley on 58 for the second-placed hosts.
