Blues got their season up and running with a hard-fought victory on their first ever visit to Huish Park.
Daniel Seaborne's own-goal at the start of the second-half was enough to send the travelling supporters home happy.
Lee Clark made one change from the side that kicked-off the season last week. Hayden Mullins came into a back-three in place of Kyle Bartley.
After fielding two different formations in the opening two fixtures, Clark opted to keep faith with the system that started the campaign against Watford.
The hosts’ first game in the second-tier of English football didn’t get off to the ideal start. After just eight minutes goalkeeper Marek Stech was forced off after a collision inside the box.
Clear-cut chances were at a premium in the opening 45 minutes; Andy Shinnie beat the offside trap but failed to connect with Wade Elliott’s superb pass.
Darren Randolph’s goal was rarely under threat from Yeovil but he was forced into a smart double save after 20 minutes to keep out Byron Webster and James Hayter.
Hayter then hit the outside of the post on the stroke of half-time after finding himself in behind the Blues defence.
Fresh from the words of Lee Clark, Blues made the perfect start to the second-half. Shane Ferguson’s corner caused confusion in the Yeovil area, and Byron Webster's clearance found the back of the net via a deflection from his teammate, Daniel Seaborne.
Buoyed by that goal, the visitors went in search of a second. Shinnie sent Lee Novak away down the right but the striker’s cross couldn’t find Matt Green in the penalty area.
Burn went close to doubling his, and Blues’, advantage after 52 minutes. The big defender found himself behind the Yeovil defence and after his attempted cross was cut out, he viscously whipped a left-footed effort inches past the top corner.
Darren Randolph was called into action on the hour-mark, the Irishman spread himself expertly to divert Webster’s free-header from six-yards onto the crossbar.
A well-worked free-kick routine almost drew the home side level but Dan Burn stretched out one of his long legs to keep out Sam Hoskins.
With 15 minutes left on the clock, Shinnie could have wrapped up the points in front of a sold-out away end. Novak played a neat pass through to Shinnie, whose first-time effort was kept out well by Gareth Stewart.
The Glovers tried to force a late equaliser and the home fans must have thought they had done it but Ed Upson’s free-kick whistled past the post.
Blues saw out the game in a professional manner and were full value for the three points.