Ulster rallied with a fine try from Marshall but it wasn't enough for the home side, as Cardiff Blues defended heroically in the final stages of the game to hold out for the draw.
The odds were stacked against the Blues after they lost Blaine Scully, George Earle and Sam Warburton to injury during the first-half.
But with the scores 14-10 at the interval Danny Wilson’s men were well and truly in the encounter and they displayed remarkable grit and determination.
Willis Halaholo and Lee-Lo caused the Irish province all manner of problems and the Samoan centre crossed for a stunning brace to add to Warburton’s earlier effort.
Cardiff Blues enjoyed plenty of possession in the opening exchanges, which also saw the hosts attempt to play their way out of their half.
For seven minutes the Blues controlled territory and possession with Alex Cuthbert carrying to good effect before Gareth Anscombe opened the scoring with a simple penalty.
However the hard work was undone as the home side pounced for a superb try. Playing advantage after a high tackle on Charles Piutau, Ruan Pienaar showed good awareness to dab a grubber behind, from the breakdown, and Jackson pounced for a converted try.
In the meantime Blaine Scully departed with a serious arm injury sustained competing for a high ball with Matthew Morgan coming on.
The Blues responded manfully and on 23 minutes they hit-back. Jarrad Hoeata put his side on the front foot with an impressive charge and offload to Rhun Williams.
They continued to go through the phases with Willis Halaholo maintaining momentum with a break and after Matthew Rees and Lloyd Williams both went close, Warburton powered over.
Anscombe converted to put the Blues back in front on 23 minutes but they were dealt a further blow as George Earle departed injured and back Ulster came again.
They kicked a penalty to the corner and regained the lead courtesy of a penalty try from a driving lineout. Jackson was once again on target, bringing the scores to 14-10.
The Belfast-based outfit came close to adding a third after Jared Payne sliced through the Blues defence and released Piutau. But the former All Black was unable to escape the clutches of Cuthbert, who made a superb try-saving tackle.
Cardiff Blues also had further opportunities to add a further try with Lee-Lo and Halaholo dangerous in midfield but the scores remained 14-10 to the hosts at the break.
Wilson’s men continued to play with plenty of attacking intent in the second-half and a superb exit and chase put Ulster on the back foot.
Quick hands from Rees and Halaholo released Williams on the wing and after surging forward he kicked on. The chase was good with Williams and Lee-Lo allowing no way out.
The home side eventually cleared but not far and some slick handling almost saw Halaholo slice through.
However referee Davies was playing advantage and the Blues struck after kicking to the corner with Lee-Lo hitting a short pass from Anscombe at pace to score beneath the sticks.
Anscombe knocked over the simple extras to give Cardiff Blues a 17-14 lead and they remained in the ascent.
Halaholo and Lee-Lo were a constant threat in midfield and a roaming Cuthbert continually made yards but they were dealt a blow when a clear high-tackle on the wing went unpunished.
A phase later Keiron Assiratti was penalised for side entry and after kicking to the corner Ulster were awarded another penalty, which Jackson slotted to level the scores.
But the Blues were undeterred and continued to cause the home side problems in attack and displayed impressive ball retention.
As the hour-mark approached Lee-Lo pounced for his second, hitting another Anscombe ball and beating Stuart Olding on the outside before evading Piutau’s last ditch tackle.
Anscombe maintained his 100 per cent record with the boot as the Blues entered the final quarter with a seven-point lead however it was not enough.
On 69 minutes Luke Marshall picked a razor-sharp line off Jackson for a converted try. The score brought the vociferous crowd back into the encounter and with their tales up Ulster surged forward time and time again.
But the Blues defended heroically to hold on for the draw and share the spoils.