Wales and British & Irish Lions hooker Rees was handed a standing ovation when he took the field as a second-half replacement – five months after he was diagnosed with testicular cancer.
McIntosh revealed how the return of the club captain, affectionately known as Smiler, lifted the Blues to recover from last week’s disappointing performance at the Ospreys.
“There was a lot of talk all week about the inspiration we took from his return from the journey he has been through,” said McIntosh.
“We saw everything that was not there last week. There was passion, heart and accuracy. That was the response we were looking for and it shows what we can do against a class team like Ulster.”
Rees came on after 58 minutes at the Arms Park at a time when his team needed him most. Leading 22-5 at half-time through Robin Copeland’s try and the boot of Gareth Davies, Ulster were mounting a comeback.
Paddy Jackson’s penalties slashed the lead to 25-23, but Davies held his nerve to convert a late kick before a desperate last-stand by the Blues defence.
The Blues began brightly against their third-placed visitors, with Ulster lock Dan Tuohy sin binned as the penalties mounted and that allowed Davies to kick the hosts ahead before a scything counter attack brought even greater reward. Full back Dan Fish caught a high ball and Copeland, who joins Munster this summer, scooped up possession, released Alex Cuthbert and then followed up to gallop over in the corner. Davies converted and added a penalty to put Cardiff 17 points in front at the break.
Ulster turned the tables after the interval but they couldn’t find a try-scoring pass, with Luke Marshall denied on the line by the outstanding Josh Navidi, while Tommy Bowe surprisingly blew a golden chance. Jackson chipped away but Davies held his nerve with his late kick to give Rees and the Blues what they deserved.