'We had our weaknesses last year here and there and we obviously try to fix those and do much better this year.
His nation's first Formula One driver, Kubica claimed the Canadian Grand Prix with now defunct BMW-Sauber in 2008 and was one of the series' most highly regarded racers before his accident in the leadup to the 2011 season.
Ricciardo finished a lowly 17th in opening practice for his home Grand Prix, completing just 16 laps of Albert Park over the course of the 90-minute session.
Vettel was fifth overall following his own trip across the grass at Turn 1 early on, and there was a sense of deja vu as he was closely followed by his former teammate Kimi Raikkonen.
"It's nice to hear that they think they have made the right choice with me, now I have to show on the track that it's really like that".
With the cars not out on the track until tomorrow, Ricciardo joined drivers on the Melbourne Walk where they arrive at the back of the pits and spend time signing autographs and posing for pictures with fans.
With neither he nor his new team mate Pierre Gasly, fourth quickest in FP2, suffering major performance or reliability problems, Red Bull may feel satisfied with the debut of their Honda partnership.
"This is going to be the toughest battle yet ... their pace is very good at the moment", the Briton said after suggesting in preseason testing that Ferrari could be as much as half a second ahead.
"If we can get that confidence and that groove back, there is a lot of lap time in that around here", he added.
Alarm bells were ringing when team engineers could be seen taking a hammer to Ricciardo's seat in the garage in a desperate bid to get the belt to fit.
Renault's Nico Hulkenberg and Daniel Ricciardo were seventh and eighth, closely matched after the Australian had a tricky day with a number of delays, first due to a technical problem and then the need to adjust his seat to reduce discomfort in the vehicle.
"We have experience, it's no coincidence that we are world champions so we have to be diligent and stay balanced", said Hamilton, who has won twice in Melbourne.
"I had this (feeling) a few times". The Pole has confessed that he is not a 100% ready for his F1 return, 20% at best, to say the least.
There's no shortage of talent behind the wheel of the two cars, with debutant George Russell winning the GP3 title in 2017 and the Formula 2 championship in 2018, while Robert Kubica is a former grand prix victor, returning to the sport eight years after his near-fatal rally accident. In a sport where times are measured to the thousandth of a second, the sight of Williams struggling to get within two seconds of their nearest rival is a depressing scene for the once proud outfit.