Mikhail Hardzeichuk and Maksim Valadzko ensured the Republic of Ireland's Euro 2016 dress rehearsal did not go as planned as Belarus ran out 2-1 winners at Turner's Cross.
Martin O'Neill made 11 changes to the side which drew with Holland on Friday evening as he prepared to finalise his 23-man squad for the tournament in France, but was left with more questions than answers.
Hardzeichuk fired the visitors into a 20th-minute lead with a stunning strike and Valadzko doubled his side's advantage with 63 minutes gone just when it looked like Ireland had finally found their feet.
Stephen Ward reduced the deficit as the introduction of substitutes Shane Long and Wes Hoolahan gave the Republic a much-needed spark in front of an expectant crown of 7,200, but the evening ultimately ended in disappointment, even for those men who will be on the plane next Wednesday.
Having seen midfielder Harry Arter leave the camp after damaging a thigh muscle in training the previous evening and James McCarthy ruled out of the final two friendlies by a similar problem, O'Neill will have hoped for positives from the men he selected on the night.
But apart from Jeff Hendrick's industry and James McClean's aggression, there was little to cheer the manager as Belarus, prompted by Ihar Stasevich, enjoyed the better of the tussle in that area of the field.
There was a significant name on the teamsheet as 40-year-old Shay Given earned his 134th cap and in the process, established himself as Ireland's longest serving international as he broke Johnny Giles' record of 19 years and 202 days, with his stint now standing at 20 years and 65 days.
However, neither Given nor those players in the starting line-up hoping to catch O'Neill's eye can have been particularly happy by the time they headed for the dressing room at half-time trailing by the game's only goal.
The Republic were able to create little of note against a Belarus side which lost 3-0 in Northern Ireland on Friday evening.
That said, they might have taken a fifth-minute lead when Ciaran Clark linked with Hendrick and then powered his way into the box to get his head to Ward's cross, although he glanced his effort across goal.
The visitors had demonstrated little as an attacking force in the early stages, but it was they who took the lead in spectacular style with 20 minutes played.
David Meyler's error allowed Hardzeichuk time and space to pick his spot 25 yards out, but the quality and pace of his shot completely defeated Given as the ball sped inside his far post.
Opposite number Siarhei Chernik was called upon for the first time 10 minutes later when Meyler thumped in a rising shot after McClean's free-kick had been blocked by the defensive wall, but the Belarus keeper was otherwise largely untroubled.
It might have been worse for the Republic had Given not got his fingertips to Valadsko's stinging 36th-minute strike, and O'Neill had much food for thought at the break.
Murphy, still awaiting his first senior goal for Ireland, might have claimed it within seconds of the restart, but he headed over from Aiden McGeady's floated cross when he might have done better.
Clark called upon Chernik once again with a 52nd-minute header after Cyrus Christie had done well to cross from the right with Ireland finally finding some momentum.
The Belarus keeper distinguished himself twice within seconds six minutes later when he parried Clark's header from a McClean corner and was then back on his feet in time to keep out Hendrick's follow-up at his near post.
But, when the game's second goal finally arrived, it did so at the other end when Valadzko got in behind right-back Cyrus Christie and then cut back inside before shooting right-footed across Given and inside the far post.
Ward reduced the deficit nine minutes later when he ran on to substitute Shane Long's lay-off and shot past Chernik to spark a late flurry, but there was to be no happy ending as Ireland slipped to a first defeat in six games.