Despite being the bigger man by some margin, Fielding struggled at times and fell into the trap of trading with Ryder on the inside throughout.
When he did find the range, Fielding was able to gain a foothold in the contest, which was a tight affair that could have gone either way.
Judges, as with the WBN Scorecard of 114-114, struggled to split the two boxers in the end but it was Fielding who realised his dream with scores of 116-113 and 115-114.
The third judge had it slightly to Ryder at 115-114 as ‘The Gorilla’ goes away to contemplate a possible return to middleweight.
Also on the Echo Arena bill, Sean ‘Masher’ Dodd claimed the vacant Commonwealth lightweight title with a hard-fought triumph over a game Lee Appleyard.
The Birkenhead man had the better skill set of the two and picked the right times to land his punches in taking rounds by sheer accuracy and volume.
After twelve exciting rounds of toe-to-toe action, Dodd was the one who had his hands raised with scores of 117-112, 117-113 and 116-112.
Amateur star Joe Cordina made an impressive debut for Eddie Hearn’s Matchroom Boxing taking out Jose Aguilar in the fourth and final round.
Cordina was on his way to a comfortable points win until the referee stepped in to the displeasure of the Nicaraguan who was completely out of his depth.
At super-lightweight, Tom Farrell remained undefeated with a ten round points victory over Tommy Carus. The Liverpool man was given the decision 97-95 with the referee.
In the first bout of the evening on Merseyside, super lightweights Steve Brogan and Henry Janes fought out a six round draw 59-59 on the official’s card prior to Ryan Mulcahy out-pointing Andy Keates 59-55 to push his record to 8-0.