It has been 28 tests since Southee took five or more wickets in an innings, at Lord's when he took 10 against England in 2013.
It's his fifth bag of five or more altogether and he has shaved a touch off his average, too, now standing at 31.53 apiece.
An ankle injury ruled him out of the recent test series in India.
Now he's feeling suitably refreshed.
"The body feels pretty good and I'm back into playing consistent cricket."
His first spell yesterday, 3-0-32-0, didn't suggest anything dramatic was afoot. Southee's radar was off and Pakistan's assertive early approach made for entertaining viewing, unless you were the bowler.
"We needed to gain a bit of control back.
"We hit our areas and with the odd one doing a little bit, and still a bit of swing, we went back to doing what we've done well for a number of years now."
Southee liked what he saw from Pakistan's best batsman Babar Azam, who made a career-high 90 before running out of partners.
"It's very promising for Pakistan to have young batsmen like that coming through.
"They've got world class batsmen in Misbah-ul-Haq and Younis Khan that he's learning from. For a young guy to come here on his first test tour, there's good signs he can play in conditions foreign to them."
Southee reckons there's still a bit in the pitch for the seamers, especially with the new ball. But New Zealand can sniff a series victory, which would be a fine way to start a busy international summer.
He's also 12 wickets shy of becoming the fifth New Zealander to 200. Southee has a potential five tests left this summer. He has taken a good step towards that milestone.