From 10 for three on a hard pitch, that had enough early-morning moisture to encourage Australia's pace attack while offering turn at pace for the spinners, opener Tamim Iqbal and Shakib Al Hasan carried the team to 165 without further loss, and they did so in just 41.3 overs, both striking half-centuries in their 50th Tests.
"(Bangladesh) might have been under-performers until a couple of years ago but they are a real deal now, especially in their own backyard.
The opening Test will be the first between the two countries since Ricky Ponting's side toured Bangladesh in 2006, clean-sweeping the series 2-0.
But Lyon insisted that while Bangladesh had the momentum, the game remained in the balance.
"To overtake him in the wickets column is something pretty special and I hold it pretty close to my heart". The wicket of Mehedi, who gifted a simple catch to Peter Handscomb at short leg, meant Lyon moved past Richie Benaud as Australia's second most prolific Test spinner, behind only Shane Warne.
That fact is spelled out by the list of leading wicket-takers since Lyon began his Test journey, a collective that is dominated by the five bowlers who have each claimed more than 200 wickets during that period.
Shakib Al Hasan and Tamim Iqbal starred with the bat for Bangladesh as they made 84 and 71 respectively.
Australia's most recent trips to the subcontinent ended in defeat.
Aussie spinners strike after Shakib, Tamim fifties
"I think Patty cracked the game open for us but then they had a (big) partnership", Lyon said.
"We have got three very good fast bowlers in the squad with Josh Hazelwood, Pat Cummins and Jackson Bird who can get the ball moving in these conditions", he said.
Shakib, off-spinner Mehedi Hasan and left-armer Taijul Islam took all 20 wickets when Bangladesh recorded its first-ever Test win over England by 108 runs in October.
Cummins (3-63) ripped through the Bangladesh top order in his first two overs to reduce Bangladesh to 10-3.
Usman Khawaja returned to the team while Ashton Agar will be playing a Test after four years. But so infrequent have meetings between Bangladesh and Australia been that it also marked the first time either had played a Test against the Aussies.
"He's got to tell himself that, really learn from that and say "I know I can do it now, just let me do it".
Soumya Sarkar was responsible for a brilliant run out to remove Usman Khawaja for one in the next over, before left arm spinner Shakib Al Hasan dismissed nightwatchman Lyon for a duck. At least we hope it's a photo shoot and he's not just forgotten his gloves, pads and helmet And one final warning before we leave you to it - don't be alarmed if Mitchell Johnson, David Warner and coach Darren Lehmann turn up at the beach while you're sunbathing.More news: The Rock's San Andreas Helped Michigan Boy Save His Drowning Brother