Marley Watkins struck twice on his Cardiff debut to save the Bluebirds from embarrassment and help them seal a 3-2 win over Sutton in the first round of the Carabao Cup.
EFL new boys Sutton struck first through Donovan Wilson and they should have moved further clear as they missed several chances in their first League Cup appearance.
It allowed Watkins to turn the tables for an underwhelming Cardiff with goals either side of the break before Josh Murphy added a late third. Sutton rallied again with a late strike from Coby Rowe, but Cardiff saw the match out.
Sutton didn't take the knee before kick-off and were booed by a sparse Cardiff crowd of 3,305.
But they got off to a dream start and went ahead in just the fourth minute.
Goalkeeper Dean Bouzanis launched a clearance downfield and David Ajiboye raced clear down the right wing and past Cardiff's rookie full-back Tom Davies before delivering a precise cross. Wilson was the man in the middle to slot home.
Cardiff confirmed before kick-off Watkins has signed until the end of August following a trial stint.
But his team offered little in attack and goalkeeper Alex Smithies had to deny Kenny Davis. Sean Morrison and Kieffer Moore did go close, but Harry Beautyman also came close to a Sutton stunner.
Wilson should also have made it 2-0 when he pounced on a shocking Morrison error, but Smithies saved the day and it proved crucial as Watkins equalised before the break.
Bouzanis somehow flapped at Watkins' weak effort when it looked easier to save.
Watkins then put Cardiff ahead at the start of the second half with a cool finish from the edge of the box.
His chances of a hat-trick were dashed when he was substituted in favour of Wales young gun Rubin Colwill.
Another Cardiff replacement in Murphy finished the job before Rowe grabbed a late Sutton consolation.
