Wales had a bonus point wrapped up by halftime and went on to win 48-7 in Rome on Saturday (Sunday) and are now the only unbeaten team in the competition.
Pivac's group have already matched Wales' Six Nations try-scoring record of 17 touchdowns, with one game still to go.
The former Auckland and North Harbour coach was unaware of that statistic, but has his mind clearly focused on the game against France, who lost 23-20 on Saturday (Sunday NZ time) for their first defeat in the series.
“Going to Paris will be a different challenge for us,'' Pivac said at the post-match press conference.
"We need to improve. We’re looking to improve every week.
“They will be a different proposition. We’ll review our performance, we’ll preview them, and we know we’re going to be in for a massive game."
This is Pivac's second season in charge of Wales since taking over from New Zealand compatriot Warren Gatland after the 2019 Rugby World Cup.
Wales could only finish fifth - with just win over Italy - in the 2020 Six Nations, and they had just one win (over Georgia) in last November's Autumn Nations Cup.
That had some Welsh critics questioning Pivac's coaching and selections, but the New Zealander is the toast of the Welsh valleys now.
Pivac said this tournament was "chalk and cheese'' to Wales' 2020 campaigns.
"We know the pain we went through in the autumn, and they were certainly not the results we were after.
"But you’re seeing some of the players who got opportunities in the autumn playing out there now in the Six Nations, coming off the bench, some getting starts.
"We’re that much better for the autumn, we’ve got a lot more depth, and we’re going to have to keep building on that depth.
"Because the big prize at the end of the day is working towards the Rugby World Cup in 2023 and this championship was always going to be a line in the sand for us.''
Pivac said Wales were "very pleased to be four from four, obviously, with an opportunity that we can finally talk about, and that’s to try and go all the way and win five from five, the Grand Slam".
He is mindful that Wales have "been on the receiving end of the result'' twice against France during his tenure.
"We know we’re going to be in for a massive challenge.
"If you asked this side coming out of the autumn whether they’d take four from four travelling to Paris for a potential Grand Slam, I think you know the answer.
"To get that bonus point by half-time and have the luxury of pulling a few of the guys off that would normally go 80 minutes was a benefit for us.
"It got a little bit disjointed but happy to keep them out at the end."
Wales hooker Ken Owens got a double and was joined on the scoresheet by No 8 Taulupe Faletau, wings Josh Adams and Louis Rees-Zammit – the Gloucester speedster who raced away for an intercept try – centre George North and replacement flyhalf Callum Sheedy.
Wales now go to Paris next weekend for a Six Nations title decider against a resurgent France.
Captain Alun Wyn Jones – the world’s most capped player – is already looking ahead to Paris.
"The excitement I feel every time I pull on this red jersey is insurmountable, so I'm looking forward to getting back to it on Monday and preparing for next weekend,’’ he told Wales’ TV channel S4C.’’
Jones said Wales were “pretty clinical, particularly in the first half’’ against Italy.
Blindside flanker Josh Navidi stood out on attack and defence to win the man of the match award.
AT A GLANCE
Wales 48 (Ken Owens 2, Taulupe Faletau, Josh Adams, George North, Callum Sheedy, Louis Rees-Zammit tries; Dan Biggar 3 con, pen; Sheedy 2 con) Italy 7 (Monty Ioane try; Paolo Garbisi con). HT: 27-7. At Olympic Stadium, Rome.