The brilliance of five-eighth Kieran Foran helped secure a crucial top-four spot for defending premier against a Titans outfit missing hooker Matt Srama (shoulder) and Queensland Origin lock Ashley Harrison (ribs).
The only downside for the Sea Eagles was a left shoulder injury to back-rower Anthony Watmough, who left the field early in the first half after suffering a burner.
Foran played a huge part in the defending premiers' convincing win, which ensured they will get a double chance in the finals and also denied North Queensland, who play Cronulla on Sunday, the chance of cracking the top four.
The Titans shocked Manly 26-14 in round seven at Brookvale Oval and it looked like another upset was on the cards when winger Kevin Gordon sped onto a deft Aidan Sezer kick in the sixth minute to score his eighth try against the Sea Eagles in six matches
But the visitors scored 18 unanswered points before halftime and the tough-as-teak Foran had a hand in all of them.
He provided a clever kick for fullback Brett Stewart to cross in the 18th minute; he and Stewart helped create a try for hooker Matt Ballin in the 28th minute and then Foran scored one himself after the halftime siren had sounded.
Not content with that magnificent effort, Foran pulled off a one-on-one strip on Titans five-eighth Sezer, who looked certain to score when the Kiwi international tackled him close to the line.
When winger Jorge Taufua crossed shortly after halftime to put Manly ahead 24-4, it appeared too big a mountain for the Titans to climb.
Industrious hooker Beau Falloon gave them a glimmer of hope when he crossed from dummy-half in the 57th minute.
Titans giant Jamal Idris suffered concussion in a clash with Taufua early in the second half but he appeared to show no ill-effects, gaining his revenge with two bell-ringers on the Manly winger.
A diving Gordon did well to stay in the field of play to score a 72nd minute try, which Scott Prince converted from the sideline to leave the Titans trailing 24-16.
There is much to like about Manly heading into the finals but coach Geoff Toovey will be concerned that his players have scored a total of only 10 points in the second half in their past three matches.