After steering his seventh boundary to the square leg fence, the celebrations were muted as New Zealand's form batsman already feared his efforts might be in vain at Grenada National Stadium.
Styris was eventually proved correct when Sri Lanka cruised to a six-wicket Super Eights victory with 29 balls to spare today, a margin that took the sheen off the right hander's second World Cup century.
Chasing New Zealand's inadequate 219 for seven, Sri Lanka coasted to 222 for four in 45.1 overs.
Styris' first hundred, 141 against Sri Lanka at Bloemfontein four years ago, was far more satisfying as it contributed to a victory.
But his defiant unbeaten 111 off 157 balls was always likely to amount to nought against a polished Sri Lankan outfit that has recently had the measure of the Black Caps.
When Styris reached his landmark, New Zealand were still struggling to make headway against what skipper Stephen Fleming later described as the best bowling collective currently in the Caribbean.
Styris said the quality of Chaminda Vaas and Muttiah Muralitharan - plus the slow nature of the pitch and New Zealand's propensity to lose wickets - made run making an exhausting, frustrating process.
"Sri Lanka bowl well in these conditions and we kept losing wickets all the way through, we couldn't put the foot down at any stage," he said.
The usually free-scoring Styris took 20 balls to get off the mark and needed 82 deliveries to post his fourth half century of the tournament.
"It was a case of trying to make the best of a bad situation," he said.
"It was an unusual feeling (reaching a century) because I'd faced 150 balls - I don't think I've done that in a one-dayer before.
"I felt quite slow at times. It was subdued (when he reached 100 off 152 deliveries), we still had a job to do for the last 10 or so balls of the innings."
Although a poor all round performance by the Black Caps - against their first serious opposition in the West Indies - tarnished his achievement, Styris was still satisfied on a personal note to continue his good touch against cricket's major players.
Styris now aggregates 379 runs from six innings - three not outs boosting his average to 126.33.
Those undefeated knocks have not artificially inflated his capabilities given they were each compiled against a top-tier nation.
He guided New Zealand home over England with an unbeaten 87 in New Zealand's Cup opener, did likewise in the first Super Eights match against the West Indies and then succeeded in defying the Sri Lankan attack in a way none of New Zealand's other specialist batsmen could emulate.
"It's been a good tournament. I've done well against the bigger teams which is pleasing. It's easy to perhaps hide some figures if you're scoring those lesser nations.
"If I can keep scoring runs against the big nations ... that's what I want to do to help the team get some wins."
Meanwhile, Styris said the abrupt end of the teams' nine-match unbeaten run would lead to much soul searching before Sunday?s clash with South Africa.
"We didn't quite have the same enthusiasm in the park," he conceded.
"There's a number of things we need to improve on for the next couple of games - rhythm's everything and momentum's everything and we just kept losing both today."