An opening defeat to Sale Shark saw Wales’ Capital Region exit the cup competition but they romped past Northampton Saints to reach the Plate final.
They were without inspirational captain Adam Thomas for the final against Harlequins and Jenkins leaded the side in his absence.
And the Wales 7s star was delighted to play his part in a thrilling fightback, which saw Cardiff Blues snatch victory at the death.
Jenkins said: “We got better as the day went on. We were gutted to lose to Sale Sharks at the start. We started really well but in the second-half we just couldn’t get the ball off them.
“We put in a great performance against Northampton Saints and then to beat that Harlequins team, after what they did in the group stages, showed great character and that we were one of the best in the tournament.
“It was disappointing not to go further in the cup but to win the plate shows we’re a quality outfit.”
The Blues trailed with less than a minute to go at the Ricoh Arena but they battled back and replacement Aron Wyn Evans powered over at the death.
Jenkins added: “We showed if we are losing with a couple of seconds to go, we have the composure and skill to get a win.
“It came down to 10 players, we said at the start that everyone would play a massive part and Aron came off the bench to score the winning try.
“It was a great finish from Aron and a great break from Declan in the build up.
“That’s testament to the squad effort. It was a 12-man effort throughout the day and I was gutted for the boys who got injured.
“Adam Thomas was a huge part of this group as a leader and player, it was gutting to lose him for the final but it just shows the character and grit of this group.”