Given their opposition that was little surprise, though in the nascent grasscourt season they did have the advantage of having spent time on the turf after playing in qualifying.
Bolt, up against the up-and-coming Scot Jacob Fearnley, went down 6-2 6-4 .
The South Australia, wearing a lot of strapping on his right knee but moving well enough, was broken early and late in the first set, but moved comfortably to 4-4 in the second.
But Bolt, watched by his partner, British player Katie Swan, then dropped the first point on serve. Suddenly the pressure rose and Fearnley broke. Bolt battled hard to lead 15-0 and 30-15 but not force a break-back point and the British No.2 served out.
Earlier on Monday O'Connell, who had been beaten by Bolt in the second round of qualifying on Sunday, found himself facing fourth seed Holger Rune as a lucky loser.
Given less than three hours notice after Matteo Arnaldi withdrew with an ankle injury, O'Connell began well forcing a break opportunity in the third game. He failed to take it however and the Dane, playing his first game of the year on grass, then settled.
O'Connell was still very much in the game when serving at 3-4, but within the blink of an eye the first set was gone 6-3. Rune, currently ranked ninth in the world, broke again midway through the second set and took it 6-4.
British wildcard veteran Dan Evans, now 35 and ranked a lowly 199, delighted a crowd basking in unusually hot London sunshine with a boilover 7-5 6-2 victory against seventh seed Frances Tiafoe. But British No.3 Cameron Norrie, a former finalist, lost to Czech teenager Jakub Mensik 7-6 (8-6) 1-6 6-1.
Roberto Bautista Agut saved a match point before beating Portugal's Nuno Borges 6-7 (8-6) 7-5 6-4, the Spaniard winning five straight match after trailing 4-1 in the second set.
On Tuesday Alex de Minaur opens play at midday local time on Andy Murray Arena in his first match since crashing out of Roland-Garros feeling burned out mentally and drained physically. Seeded five he faces Jiri Lehecka.
The Czech, ranked 30, is a potentially tricky opponent. De Minaur, who slipped to 12 in the rankings updated yesterday having not defended his title at Rosmalen last week, won their previous meeting, indoors in the 2023 Davis Cup, but Lehecka KO'd two top-20 players on grass on his last Wimbledon visit, in 2023.
At the same time on court 5 Alexei Popyrin, now ranked at a career-high 21, plays Aleksandar Vukic in an all-Aussie affair while Jordan Thompson goes later against Jaume Munar.
In Nottingham James McCabe, having come through qualifying, faced British wildcard George Loffhagen in a repeat of their final at the same venue on the lowest tier world tennis tour last year.
McCabe won that one 6-0 6-1 and it was the same result at Challenger level, albeit much closer, as the Australian won 6-3 7-6 (7-4).
