Ruddy, 18, who was making his home debut after his loan move from Everton, first denied Isaiah Rankin with a one-handed stop in the 65th minute.
He then frustrated Lloyd Owusu with a point-blank save 13 minutes later as Walsall rode their luck to secure a share of the spoils.
Brentford, who had done the double over Walsall last season, enjoyed the majority of possession against Paul Merson's side.
But some last-ditch defending and the display of Ruddy conspired to frustrate a Brentford side who could at least take heart from ending a run of back-to-back defeats.
Walsall made a fast start but were unable to turn that early pressure into goals when Anthony Gerrard saw his shot blocked before Merson pulled a free-kick wide.
Having survived that double early scare Brentford were unfortunate not to break the deadlock themselves.
Sam Sodje saw his 16th minute header cleared off the line by Craig Pead before Darren Pratley shot just over the bar 11 minutes later.
But it was Walsall striker Matty Fryatt who squandered the best chance of the half when he headed straight at goalkeeper Stuart Nelson from close range after Merson had whipped in a 33rd minute free-kick.
Merson looked the man most likely to create an opening for Walsall but his evening came to a painful end nine minutes before half time when he was stretchered off with a groin injury.
Walsall's problems would have become even more serious but for Ruddy saving them in the second half.
First he threw out his right hand to turn Rankin's shot around the post after a knock down by Owusu.
The England under-19 international then produced an instinctive save to turn away a header from Owusu after a left-wing cross from Alex Rhodes.
All Ruddy's hard work was almost undone two minutes from time when Jorge Leitao just failed to turn home a header.