A second half Kris Doolan strike was enough to secure Partick's place in the next round of the Ramsdens Cup but Clyde can be satisfied with a wholehearted display that gives manager Jim Duffy a solid platform to build on.
There was no disputing the superior quality of the first division visitors who dominated for long spells in a keenly contested season opener at Recreation Park.
The Jags may have expected to cruise to victory against a team two divisions below them but Jackie MacNamara's side were confronted by a well-organised and committed rearguard with Iain Gray and David Marsh working successfully in tandem at the heart of Clyde's defence.
Full-backs Lee Sharp and Gavin Brown also had their work cut out to deal with regular forrays down the flanks from Stephen O'Donnell and Staurt Bannigan who was named the sponsor's man of the match, but the Clyde pair were also among the best performers in red and white.
Partick made their intentions clear from the start and it was a good ten minutes before Clyde managed to work their way deep into Partick territory when Daniel Fitzpatrick latched onto a loose pass from Hugh Murray and nursed the ball forward to Stuart McColm who was only just beaten to the ball by an alert Scott Fox who was quickly off his line to collect.
Soon after that Partick's Chris Erskine picked out Christie Elliot with a neat flick-on. The striker raced towards Clyde's 18-yard-line but before he could muster a shot, Gray nipped in to clear the danger with a sense of timing that was to serve Duffy's team well throughout a sun-kissed encounter.
Clyde's Brown was next to try his luck but his long range shot was more in hope than expectation and never looked like troubling Fox who looked on as it sailed well wide.
A more promising move unfolded when Stuart McColm chased down a through ball that held up kindly on the artificial turf only for the alert Partick keeper to snuff out the danger with a no nonsense punt.
At the other end Barclay was called into action to deal with a shot from Steven Lawless but the Jags wide man could not capitalise on a Paul Hay error that had gifted Lawless easy possession in the middle of the pitch.
Lawless threatened again on the half hour mark when he stood over a free kick, front and centre of Barcley's goal. He managed to curl the ball round Clyde's wall but his effort slipped over and drew welcome cries of derision from the home support.
Clyde were struggling to keep Partick at bay but Marsh proved his worth when a superbly-timed tackle put the brakes on a tidy move involving Elliot and Stephen O'Donnell who was a constant menace on the right flank.
The next Partick move brought out the best in the Clyde keeper when he showed no concern for his own safety with a brave dive at the feet of Bannigan who was preparing to unleash from close range after worming his way into the six-yard-box.
Partick started the second half with a spring in their step and an early Erskine effort was a taste of what was to come. O'Donnell followed that up with a galloping run and cross inside to Sean Welsh whose tame effort from the edge of the box was easy meat for Barclay.
Clyde had more to give however and a spell of pressure had the Jags sweating until Sharp's back post delivery was too heavy and dipped harmlessly behind Fox's goal.
Barclay had more to do at the other end when he pulled off two solid saves to turn a well-struck Erskine shot round the post before a close range Welsh header thumped straight into the safety of the keeper's arms.
Partick were starting to threaten more and when O'Donnell skipped across the face of Clyde's goal he looked odds on to pick his spot beyond Barclay but the home side crowded round the foraging defender and his eventual improvised effort was blocked before it reached the keeper.
A few Clyde supporters could have been forgiven for thinking extra time was on the cards but on 74 minutes Partick made the breakthrough. Doolan had only just came off the bench when he pounced on an unfortunate error from Barclay who let a Welsh shot from outside the box bounce off his chest and into the path of the striker who had the simple task of rounding the grounded keeper and slotting into an empty net.
You had to feel sorry for Barclay who, until that moment, had done nothing wrong. To their credit, Clyde did not throw in the towel and had luck been with them in the dying minutes Kevin Watt's overhead kick could have brought Clyde level but his valiant effort didn't have the necessary power to beat the Partick keeper. As it was Fox clutched the ball comfortably to ensure a worthy but hard-fought win for the visitors who are sure to feel the stresses and strains of having come up against a well-drilled Clyde who battled hard from start to finish.