The Roosters, 1-3 to begin their 2025 campaign, were outclassed by a Jayden Campbell-inspired Titans outfit, who powered home in the final quarter of an hour at Allianz Stadium on Friday.
It means the Roosters have conceded 126 points through their first four games, their worst defensive display since the 2016 season when they finished second-last.
Robinson's side completed at just 59 per cent and made 15 errors and will have to find form quickly given they play arch rivals South Sydney next week.
"If it was high 50 (completion rate), that's not NRL standard," Robinson said.
"Pressure is a big part of the way that the NRL is played and when you build none you won't get those decision-making errors out of the opposition."
Robinson's side led 12-8 after Dom Young crossed early in the second half following a Campbell penalty goal for the Titans.
Gold Coast five-eighth AJ Brimson and Roosters cross-code convert Mark Nawaqanitawase had traded tries in the first half.
Surprisingly, the Roosters had failed to convert six first-half linebreaks and they were made to pay when five-eight Sandon Smith pulled the wrong lever when his side led 12-8 with 20 minutes to go.
Smith - under added scrutiny following speculation his side may sign Daly Cherry-Evans - looked to fire a short ball to Angus Crichton but his pass was picked off by Campbell, who raced 100m to score.
Over the next 15 minutes, the Titans rammed home their advantage with Campbell in control and playing like a natural No.7.
The 25-year-old - filling in for Kieran Foran - helped further extend his side's lead when a forced drop-out led to Phillip Sami's 70th minute try.
Sami's try opened up a six-point gap from which the Roosters never recovered.
Brimson and captain Tino Fa'asuamaleaui crossed in the final 10 minutes to give the Titans a 2-1 start ahead of next week's home clash with the Dolphins.
"He (Campbell) is building, which is good, but it's up to us to keep giving him a good platform to build on," said Titans coach Des Hasler, whose side ended an 11-game losing streak against the Roosters.
"He came up with some big plays. Both boys (Campbell and Brimson) are very instinctive, so that's always hard to defend."
Nawaqanitawase and lock Victor Radley passed head injury assessments for the Roosters and should be cleared to face Souths next week.
Prop Spencer Leniu's presence is under a cloud after he was placed on report for a high shot on Titans front-rower Reagan Campbell-Gillard.
