There was limited lateral movement off the pitch, although on 24 he snicked a shorter length ball to Alastair Cook at first slip from debutant Mark Wood. A third umpire check revealed a no-ball and Guptill capitalised on his reprieve. Previous concerns over defensive frailties at test level were largely tempered.
"It was a nerve-wracking time," Guptill said. "The umpire nodded his head, I started walking, but I got a second life. He [Wood] has some good skills and could be a menacing international bowler.
"Being a more front-foot-oriented player, I knew they'd bowl shorter to prevent me driving.
"The pitch is starting to flatten but I expect it to get slower on days four and five, which will make it difficult to bat on."
Latham and Guptill posted the second-highest partnership by a New Zealand opening pair at Lord's, falling short of the 185 set by John Wright and Trevor Franklin in 1990.
"Our partnerships cemented our dominance of the day," Guptill said. "It was pleasing to score a few runs, but the partnership Tom and I created set the game up for us before Kane and Ross picked up where we left off."
Williamson and Taylor resumed last night having posted 155 for the third wicket as part of New Zealand's 303 for two, leaving the visitors 86 runs behind.
This season, Guptill's been in form at Derbyshire, scoring 451 runs at an average of 112.75, including a first-class best of 227 against Gloucestershire.
His resume also includes being the top runs-scorer at the World Cup, when he made 547 at 68.37 with a strike rate of 105.
His coup de grace, the 237 not out in the quarter-final against the West Indies in Wellington, was the highest score in 11 editions of the tournament.
Guptill's 150 off 210 balls against Worcestershire prompted coach Mike Hesson to all but ink his name on the Lord's team sheet. That innings also helped New Zealand to a 15-run victory in the four-day warm-up match.
"I just wanted to continue batting as I have been," Guptill said. "My decision-making was better than a lot of my previous test matches."
Williamson was assured and all class, falling into test mode immediately without any hint he's been playing Twenty20s and ODIs for five months.
"He's a bit of a freak," Guptill said. "He just seems to keep scoring runs, and finding ways of doing it, with not a lot of batting time lately."