Mark McGuinness capped his first appearance of the season with a goal to help Cardiff beat Bristol Rovers 2-0 in the EFL Cup first round.
Defender McGuinness - a target for Luton Town - headed home an Ollie Tanner corner on 68 minutes to put the Bluebirds in front.
Wales international Rubin Colwill sealed the win with an injury time strike, completing a sweeping counter.
After a tepid first half the game changed around the hour mark with a flurry of substitutions which enlivened the home side with Ollie Tanner and Michael Reindorf impressing.
Earlier Cardiff debutant Alex Robertson, a summer signing from Manchester City, had seen two shots blocked while Rovers striker Promise Omochere had blazed over at the other end.
And after soaking up pressure for much of the second half, the deadlock was finally broken when McGuinness' header sent Rovers towards their sixth consecutive defeat in this competition.
Colwill, who had looked bright for much of the contest, had the last laugh to give Erol Bulut's side their first win of the campaign.
Cardiff City manager Erol Bulut told BBC Sport Wales:
"It is important that players come on and change the game and change the result, but we need it in the league games not just the cup games.
"First half it was not exactly what we wanted to show, we played too slow, we thought too slow.
"Second half was much better, and we created chances to score. There could have been more goals today."
Bristol Rovers manager Matt Taylor said:
"I am disappointed. I thought we created the best chances in the first half, the team was set up well but we have to be better with the ball and in our attacking moments.
"We are a little bit aggrieved because we thought it was a foul on Luke McCormack, they countered against us and we defended the set piece poorly.
"It was a little bit of a lesson for certain personnel in relation to those moments but I have to be honest I am disappointed."