But skipper Ramsey was picked out by Craig Bellamy, on his 78th and final Wales appearance, and slid the ball under Thibaut Courtois to earn the visitors a hard-earned 1-1 draw.
This could prove to be Coleman's last competitive game in charge of Wales, with his contract effectively up after next month's friendly against Finland and talks of a new deal having stalled.
They had an early chance when Ramsey's reverse pass found Andy King, but his pull-back did not quite reach Hal Robson-Kanu.
Belgium enjoyed their own spell of pressure, with Kevin Mirallas failing to find a team-mate after his Everton colleague Romelu Lukaku had beaten James Collins to a flick-on.
Lukaku then forced Wayne Hennessey into his first save on 15 minutes after Kevin De Bruyne had put the forward away, while at the other end Robson-Kanu skewed wide after a driving run from Ramsey.
Mirallas fired wide after nipping in ahead of Collins to meet a Toby Alderweireld centre, but with Ramsey pulling the strings Wales were posing attacking questions of their own.
But they survived a major scare seven minutes before the break.
Alderweireld flicked the ball over two defenders before getting away a volley which deflected off Collins and rattled the bar, before Mirallas fired wide following up.
Hennessey then could not hold a De Bruyne shot before Lukaku headed inches wide from Sebastien Pocognoli's teasing cross.
Robson-Kanu fired tamely at Thibaut Courtois as Wales responded, before having a decent penalty appeal turned down on half-time when Simon Church went over in the box under Daniel Van Buyten's tackle.
Home side lift further
Belgium piled on further pressure after the break with Thomas Vermaelen firing wide from Lukaku's pass.
Welsh hopes suffered a blow as Collins limped off with an ankle problem and Cheltenham's Wilson came on to win his first cap in his place.
But the visitors continued to battle gamely, and Ramsey and Church combined to engineer a shooting opportunity for David Vaughan, whose effort was deflected over the bar.
Belgium introduced Eden Hazard in place of Nacer Chadli and the Chelsea man almost made an instant impact as he picked his way past several defenders only for Hennessey to save with his legs.
De Bruyne finally broke Welsh resistance in the 65th minute pouncing on a defensive error from debutant Wilson to fire low into the bottom corner.
But Wales rallied and Courtois just about kept out a glancing header from substitute Sam Vokes and a shot from Vaughan during a goalmouth scramble from a Ramsey free-kick.
Coleman then handed 16-year-old Harry Wilson a first cap to make the Liverpool winger the youngest player to ever represent Wales, and within seconds of his introduction the visitors levelled.
Bellamy, with his last telling contribution for his country, picked out Ramsey and the Arsenal man slotted calmly under the keeper to earn Wales a draw against the odds.