The Motherwell goalkeeper denied Simon Mensing three times in around five minutes as Hamilton pushed forward after an even first half.
But the home side could not maintain their pressure and John Sutton missed a good chance to take the points across the M74.
A scrappy goal from Lukas Jutkiewicz was all that separated the Lanarkshire rivals the previous weekend in a tight rearranged match at Fir Park, and the latest derby was even closer.
Well have now lost just one goal in seven SPL games under Brown and they maintain fifth place in the table.
Both sides welcomed players back from suspension with Mark McLaughlin replacing Kyle Wilkie for the hosts and Giles Coke recalled in place of Ross Forbes for Well.
Hamilton began well and Ruddy got down to push away Marco Paixao's 20-yard drive following a Dougie Imrie lay-off.
Ruddy was beaten in the 10th minute when he misjudged Brian Easton's long free-kick but McLaughlin's backward header looped off the top of the bar.
Jutkiewicz had a low drive saved from 25 yards as Motherwell settled and their best chance of the half soon fell to Coke, but he volleyed high over from eight yards after Sutton headed down Jim O'Brien's deep cross.
Tom Hateley was inches away from repeating the 25-yard free-kick strike that helped Motherwell claim a midweek point against Rangers, but there was little goalmouth action in the latter stages of the half as both teams cancelled each other out in the middle of the park.
Hamilton began to take control after the break and Brown made a double switch 10 minutes into the half in a bid to jolt his team into action.
Michael McGlinchey came on for his debut up front with Sutton dropping back into the hole vacated by Coke, and Chris Humphrey replaced O'Brien on the right wing.
However, Ruddy soon saved Motherwell several times in quick succession, first acrobatically pushing over Mensing's header from a Marco Paixao free-kick.
Accies kept the pressure on and Ruddy tipped over David Elebert's header before getting down to hold Mensing's long-range drive.
Mensing had another good chance when the ball fell for him 18 yards out after a mix-up between Ruddy and his defence, but the goalkeeper charged forward and blocked the midfielder's low shot.
Ruddy then scrambled across his goal as Flavio Paixao's deflected shot from distance span just wide.
Motherwell had perhaps the best chance of the game in the 69th minute though when Stephen Craigan's up-and-under left Hamilton waiting in vain for an offside flag, but Sutton struck over from eight yards after chesting the ball down.
The visitors improved and pushed Hamilton back for much of the final 20 minutes but McGlinchey and Steve Jennings were off target from long range.