The on-loan Manchester City man never looked like disappointing a capacity crowd and almost enjoyed a dream start but his close-range shot was saved by Neil Sullivan.
However, it did not take long for Bellamy to make a telling contribution and he played in Jay Bothroyd who opened the scoring after 36 minutes.
Cardiff doubled their lead in the 62nd minute when Chris Burke, who had earlier came on for Michael Chopra, crossed from the right for Bothroyd to head in his second of the game.
Bellamy was getting all over the pitch and six minutes later he found himself in the left-back area and launched a fine ball to set Burke free and he made it 3-0 with aplomb.
It was almost inevitable that Bellamy would get a debut goal and so it proved when Bothroyd was upended, allowing the 31-year-old Wales striker to flash home a superb free-kick from 35 yards.
Cardiff started well and Bellamy sprung into action after only two minutes, latching onto a ball from Chopra but his lofted effort was kept out by Sullivan.
However, Doncaster were looking dangerous themselves and a clearance from Peter Whittingham fell to Brian Stock who flashed a long-range effort just wide.
Minutes later Stock fired in a shot from 20 yards but Cardiff goalkeeper David Marshall did well to tip the ball around the post.
Doncaster looked the more likely to open the scoring but with 15 minutes gone Chopra was sent clear and tried to lob Sullivan, who made a superb save with his fingertips.
That proved to be Chopra's last meaningful contribution as his afternoon was brought to a premature end just after the half-hour mark when he limped off to be replaced by Burke.
The loss of Chopra was a blow for Cardiff but they took the lead five minutes later. Bellamy played a good ball into Bothroyd who miscontrolled before slipping the ball past Sullivan.
Cardiff immediately went in search of a second and four minutes before half-time Burke crossed into the path of Peter Whittingham who looked likely to score but completely mis-hit his effort.
All eyes were on Bellamy once again at the start of the second half and his pace continued to trouble the Doncaster defence.
For all Bellamy's intelligent running, it was Doncaster who once again looked the more threatening and they almost drew level in fortuitous circumstances when James Coppinger's mis-hit cross clipped the bar with Marshall scrambling.
Burke continued to look lively and it was inevitable that he would be involved in Cardiff's second goal after 62 minutes.
The former Rangers man skipped past George Friend and got to the right byline before crossing for Bothroyd to head in his second.
Six minutes later Bellamy's excellent ball upfield found Burke who held off Adam Lockwood and fired superbly past Sullivan.
The home crowd were itching to see Bellamy grab a goal and with six minutes remaining Lockwood fouled Bothroyd and Bellamy, who had also received a booking for dissent, fired in superbly.