Home side ensure they take a narrow lead into the second leg after victory at Selhurst Park on Tuesday night, but the tie is far from over a hard-fought first leg
For much of the match it was the visitors applying the pressure, but they struggled to find the opportunities in front of goal, while Palace were considerably more clinical.
Anthony Gardner gave Palace the win with a header just before half-time, and despite a couple of chances in the second half, Cardiff could not make the most of their pressure as the hosts defended well.
Both sides made wholesale changes from their respective FA Cup defeats at the weekend as Palace defender Peter Ramage remained the only player to retain his place from the 1-0 loss at Derby County.
Cardiff also made 10 changes following the 4-2 defeat at West Brom, with goalkeeper Tom Heaton the only player to start again on Tuesday.
The match was played at a good pace throughout with both teams coming out for a win despite the match being the first leg, but it was the visitors who began to take control.
The opening minutes saw the teams spar for possession, but Cardiff started to gain headway as they won set-piece after set-piece, but although Ben Turner went close from a Peter Whittingham corner, they could not open the scoring.
Just before the 20-minute mark, Glenn Murray, Palace’s hero from the victory at Old Trafford, should have done better with a header, but after getting on the end of a corner he put his header wide even though he was unmarked.
If Palace were not disappointed enough, they would soon be ruing a great chance as Kagisho Dikgacoi’s effort was foiled by the goalkeeper.
The ball rolled perfectly to the South African as Murray flicked on a low cross from the left-hand side, but after taking a touch to set himself, his shot was parried away well by Heaton.
Cardiff were soon back on the attack, however, as Kevin McNaughton’s low cross was deflected to Kenny Miller on the penalty spot, but after skipping past one challenge when he probably should have shot, he was crowded out.
Miller seemed insistent on making up for his previous miscalculation and he was soon trying his luck once again, this time with a more audacious attempt from the corner of the penalty area, but his curling strike flew just past Julian Speroni’s left post.
Despite Mackay’s Cardiff arguably having the better of the first half, it was the hosts who went into the break in the lead as Gardner struck just before half-time.
Darren Ambrose whipped in an inviting free kick from the left and Gardner, using all of his six-and-a-half-feet, rose to head in at the far post after Heaton failed to deal with the delivery.
The second half picked up where the first left off as Palace looked the more dangerous in front of goal and young Wilfred Zaha continued to dazzle the Cardiff defenders with his brilliant footwork.
Zaha, who supplied some decent crosses in the first half, was at it again six minutes into the second period as he tricked his way past three Cardiff players down Palace’s left wing, but his teasing cross was not met by a team-mate, while a few seconds later Chris Martin, on loan from Norwich City, poked just wide.
Cardiff, already chasing the game, twice came close to an equaliser as Joe Ralls’ half-volley was tipped round the post by Speroni, while Miller found the net from the resulting corner, but it was harshly ruled out.
As the second half continued, the visitors were finding it increasingly difficult to make the most of the pressure they were asserting as they created very little.
The hosts themselves appeared reluctant to commit to attack, opting to sit back and soak up pressure with Cardiff failing to break them down.
Mackay’s team managed to carve open one half-opportunity as Darcy Blake charged down the right before finding Whittingham in the area, but his attempted shot was deflected towards Stephen McPhail, and the Irishman could only fire an effort over the bar.
Cardiff continued to search for that elusive goal and Whittingham went close as stoppage-time approached, but his left-footed shot from the edge of the area was deflected just past the right-hand post and Palace held on for the narrow win.