While Sydney Roosters and Canberra were highly impressive in shoring up a week off and home-ground advantage in their respective preliminary finals, the real eye-openers for this columnist were the performances of Manly and Parramatta.

Manly, despite the absence of key personnel Tom Trbojevic, Martin Taupau, Joel Thompson and Curtis Sironen, dominated a Cronulla side that was close to full strength to prevail 28-16 at Brookvale.

The following day, Parramatta humiliated Brisbane in a 58-0 slaughter at Bankwest Stadium, the largest winning margin in finals history.

What made both victories even more remarkable were the rungs each team occupied on the competition ladder just 12 months earlier.

Parramatta finished outright last in 2018, with six wins for the season. Manly were one win and one position ahead of the Eels, although their defensive record (622 points conceded) was the worst in the NRL.

Somehow, in the space of a year, both the Eels and Sea Eagles have transformed themselves from dysfunctional easybeats into teams capable of progressing into week two of the play-offs.

To hell with cleaning out rosters in an attempt to set their clubs up for long-term future success. Both have just got on with the business of winning games and making the most of the resources at their disposal.

Parramatta coach Brad Arthur reinforced his wooden spoon squad with some strategic recruiting.

He signed Junior Paulo (Canberra) and Shaun Lane (Manly) to add some much-needed size to his pack. Blake Ferguson was imported from the Roosters to provide the power and pace the Eels had been lacking since the departure of Semi Radradra, while Waqa Blake arrived mid-season from Penrith.

It's fair to say none of those players would have joined Parramatta had their former clubs shown more interest in retaining them.

Then Arthur struck gold by promoting a little-known Fijian winger to make his debut in the season-opener against Penrith. Maika Sivo has since been a sensation, scoring 22 tries in 24 games.

With the addition of just five players, Arthur has improved the Eels from the worst attacking team in the NRL last season (374 points for) to the third best this year (533 for).

Defensively they are also 77 points better. That's a 236-point turnaround, or around 10 points per game, not including last week's 58-0 whitewash.

Manly's resurrection has perhaps been even more spectacular.

When Des Hasler returned to the club he steered to the 2008 and 2011 premierships, his only notable imports were Kane Elgey and Brendan Elliot, both of whom were Gold Coast discards.

In the pre-season wooden spoon betting, Manly featured prominently alongside the Eels, Wests Tigers, Canterbury and Titans.

But Hasler's knack of extracting the best from his players was highlighted by Elliot - a fringe first-grader during his two years with the Knights - scoring two tries in last week's win against Cronulla. Under Hasler, the flimsiest defensive team of 2018 emerged this season as the fifth best.

All of which is a reminder that the Knights, four years after commissioning Nathan Brown to "rebuild" the club following their 2015 wooden-spoon campaign, finished this season in 11^th place.

Promisingly placed at the halfway point in proceedings, they lost eight of their final 10 games, culminating in a 54-10 last-round hammering from Penrith.

The bottom line is both Manly and Parramatta have achieved inside 12 months what was beyond Newcastle during Brown's underwhelming four-year tenure.

Maybe incoming coach Adam O'Brien will deliver the success Newcastle's fans - the most loyal and parochial in the NRL - are craving. But there are no guarantees, and given that the Knights are officially the NRL's worst-performed club this decade - on a win-loss basis - he faces an enormous challenge.

I have been encouraged to hear, however, that O'Brien wants attitudes at the club to change, and is insisting on no further reference to the phrase "rebuilding".

"Rebuilding", when you think about it, is a convenient euphemism for "accepting mediocrity".

As Manly and Parramatta have shown, why not just renovate and repair?

They're not the first clubs to rebound in a short space of time.

In 2012, the Roosters finished 13^th. A year later they were premiers. Under Brian Smith they improved from 2009 wooden spooners to 2010 grand finalists.

Cronulla, last in 2014, were premiers two years later. Penrith performed a similar worst-to-first turnaround between 2001 and 2003.

Even the Knights, after collecting their first spoon in 2005, were a top-four team the following year.

Their modern-day counterparts are, presumably, embarrassed about how this season imploded. Knights fans can only hope the success of Parramatta and Manly motivates them to make amends next year.