There were some blowout scorelines and stunning individual performances.
While the struggles worsened for some of the competition's bottom-ranked teams and crises deepened for new coaches like Todd Payten and Trent Barrett.
Round four taught us plenty about how this season is playing out - here are all the big talking points.
Thursday, Friday blowouts validate NRL's class gap debate
Round four reaffirmed something we probably knew last year, and that's that the bottom four sides have a long way to go.
The blowout scorelines from the opening matches of round four validated arguments for there being a dearth in quality between the competition top and bottom-ranked teams.
Penrith, Melbourne and South Sydney were given training runs by the Sea Eagles, Broncos and Bulldogs respectively, with an aggregate score of 124-12 highlighting the sheer class differences.
Various factors like salary cap management, coaching and injuries have seen the NRL dominated by the same clubs for a number of years now. But in 2021, the divide in class between the 16 clubs is becoming increasingly evident.
While the Bulldogs and Broncos can be somewhat excused given they have new coaches and systems in place as a result, the performances of the Sea Eagles, whose roster and coaching staff from the past two years has largely remained the same, is unacceptable.
Titans yet to prove finals nous
Until they can match it with a top-four side, the Titans haven't yet proven the hype around them.
Going into the new season, Justin Holbrook's side were one of the more talked about following their acquisition of Origin forwards Tino Fa'asuamaleaui and David Fifita.
Both recruits have been excellent and the Gold Coast were humming off big wins over the Broncos and Cowboys.
There were moments in the loss to Canberra they could've set up victory but lacked the finesse and polish in attack.
Until the Titans find that against some of the bigger teams, they can't yet be classed as a finals-quality team.
Solution a long way off for Cowboys
Not even mass team changes could spark the stumbling Cowboys into action as they suffered another heavy loss, going down 48-10 to the Sharks.
Payten axed Jake Clifford for Ben Hampton at halfback, dropped Esan Marsters and put Coen Hess to the bench, but that did nothing to fix his side's flimsy defence.
Things are going from bad to worse for Todd Payten in his first season as coach in Townsville, but none bigger than the fact his side simply aren't putting in the effort defensively.
The Cowboys have now conceded 141 points for an average of 35 points per game but most glaringly have missed the most tackles (144) in the competition.
In his first full season as an NRL coach, Payten will be given some leeway but he simply must improve the performances or patience will quickly start to run out.
Tariq Sims is officially back
He was one of the most under pressure players at the Dragons entering the new season, but after a couple of lean years, Tariq Sims is back.
The former NSW Origin forward was at his bullying best on the Dragons' left edge and won in his one-on-one battle with former teammate Tyson Frizell.
Sims scored two tries in a 10-minute period, one line-break, 129 metres and three tackle breaks in a man-of-the-match display in the 22-13 win over Newcastle.
The effort followed last week's blitz against the Sea Eagles and confirms Sims' return as a force for the Red V.
Injuries have restricted Sims' output over the past two seasons, but after completing a full pre-season issue-free, Sims has rediscovered his best form under Anthony Griffin, much like many of his senior teammates.
Sam Walker is as tough as he as skillful
The 18-year-old Roosters halfback made his highly anticipated debut against the Warriors at the SCG on Sunday and showed exactly why the wraps on him were so high.
Walker played 80 minutes as the hosts ran out 32-12 winners, over-running a fast-starting Warriors outfit.
The young Queenslander doesn't appear NRL ready in stature just yet, but his confidence to run the team on both sides of the ruck will calm the nerves of Roosters fans following Luke Keary's ACL injury.
Keen to test the youngster, the big Warriors pack made Walker earn every pass and kick, not missing any chance to get physical with the playmaker, and every time, he dusted himself and called for the footy at the next opportunity.
Get used to watching this bloke for the next 15 years.
Parramatta are just as much of a threat as last year - if not more
There were plenty of expectations surrounding the Parramatta Eels in 2020, and rightfully so. Their roster was strong, and they seemed primed for big things.
A late-season slide saw them go out of the finals in straight sets, but the way they have started 2021, they are certainly looking the goods.
Clint Gutherson is continuing to be Mr.Consistent and their halves are starting to find their groove - but it is the emergence of Reed Mahoney that is going to take them to the next level.
He has been brilliant out of dummy-half in the opening four rounds, with his kicking game taking plenty of pressure off Dylan Brown and Mitchell Moses.
Their forwards are clearly still a strength, and they may have even improved with the signing of Isaiah Papali'i.
Parramatta are looking like a real contender this year - will they finally break their lengthy premiership drought?
