Mark Ramprakash's third successive Championship century put Surrey in command on day one against Sussex, the home side reaching 256-2 at the close.
The acting skipper, who made an unbeaten 200 against Somerset to follow his 100th first-class hundred, hit 18 fours and a six in his unbeaten 133.
He shared an unbroken 216 with Jon Batty, who was on 96 when bad light ended proceedings prematurely.
Left-arm seamer Jason Lewry took two early scalps but Sussex had a long day.
It is also the prolific Ramprakash's third successive century against Sussex, and his 10th against the current champions.
He may find himself in trouble with the authorities, however, after a confrontation with Sussex batsman Murray Goodwin that led to the volatile Surrey captain having to be restrained by the umpires.
Surrey decided to bat on an overcast morning, but lost Stewart Walters for a duck in the third over when he drove loosely at Lewry and was caught by Ollie Rayner at slip.
After a short delay for rain, Lewry claimed his second wicket when he surprised Scott Newman (18) with some swing and bounce and took the edge.
Sussex captain Chris Adams failed a fitness test on his injured ribs and Michael Yardy took charge, but his swing bowling mainstay Lewry could not regain his rhythm in his second spell as Ramprakash and Batty recorded a century stand in 42 overs.
Batty celebrated the announcement of his benefit in 2009, reaching fifty in the 54th over with another stylish drive through the covers.
Ramprakash moved into the nineties with successive fours off Michael Thornely, and reached three figures from 168 balls in the 68th over.
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