McCullum's run-a-ball innings of 97 shone brightly on a damp, chilly London day as New Zealand ended on 208 for six after being sent in to bat by home captain Michael Vaughan.
A standing ovation from the Lord's members still didn't lighten the wicketkeeper's mood after he fell for successive test 90s at the home of cricket.
Four years after being caught behind for 96 here, his 170-minute stay was ended by England spinner Monty Panesar who snuck a delivery through the gate, via pad, onto off stump.
"It's bittersweet, obviously disappointing not to have made 100 and still be at the wicket at the moment," McCullum said.
"But I'm still very proud to have stepped up in the circumstances, a move up the order and another opportunity back at Lord's where the last one was pretty bittersweet as well."
If it weren't for McCullum, who added 99 off 19 overs with Jacob Oram to lift New Zealand from 104 for five, the test may have been gone already.
But with Oram resuming tonight (NZT) on 23 and captain Daniel Vettori on five, there was some hope.
"To be 200 for six and arguably our two best batsmen at the crease is not a bad position," McCullum said with a wry grin.
"Somewhere around 300-350 would be a fantastic effort after losing the toss on that wicket in those conditions.
"If we can do that we'll head into our bowling with a lot of confidence that we can certainly hold our own in this game and give ourselves an opportunity down the track."
McCullum strode to the crease at his new position of No 5 with New Zealand teetering at 41 for three, the England seamers getting plenty of assistance after a 140-minute rain delay.
He chanced his arm, twice chipping the ball just over the offside fielders, but safely registered his ninth test half-century -- and fifth against England -- off 65 deliveries.
The next 47 runs took just 32 balls and included two memorable sixes -- a lofted straight hit off Panesar then a lofted cover drive off a stunned Stuart Broad to take him into the 90s.
He cruised to within three of a magical century before, in his words, "I missed a straight one" and slumped over his bat.
With their inexperienced top order, New Zealand needed a lucky break and they didn't get it when Vettori called incorrectly at the toss.
Openers Aaron Redmond and Jamie How were back in the famous pavilion inside eight overs, both nicked out by England paceman James Anderson who ended with three for 42.
After excellent leadup form, Redmond's debut lasted just five deliveries when Anderson seamed one away and Alastair Cook snared him at third slip.
He became the first New Zealand opener to score a duck in his first test innings since Ken Rutherford in the West Indies in 1985.
James Marshall, in his first test in three years, was caught behind off an Anderson no-ball on nine and batted 104 minutes for 24 before Stuart Broad found his edge.
Ross Taylor had a bizarre stay, cracking a boundary off his first delivery before an awful mix-up with Marshall saw them stranded at the same end but Anderson botched the run-out attempt.
Then on 19 he launched into a wild hook shot off Broad and skied a simple catch, before debutant Daniel Flynn was unluckily bowled off his thigh pad for nine.
England paceman Ryan Sidebottom caused the batsmen few worries after his man of the series performance in New Zealand, bowling 18 wicketless overs.
