Coyle is changing the culture at the Reebok Stadium, but Bolton's usual belligerence was needed to ensure victory over a team whose highest finish since 1959 was already assured.
Bolton are one of only two sides to win at St Andrew's this season and deserved this affirmation of their convincing escape from relegation.
Final push: Fabrice Muamba (left) and James McFadden gave little impression that it was the last game of the season with little to play for
Referee Kevin Friend made some contentious decisions, failing togive Bolton a penalty when Liam Ridgewell handled and awarding adubious spot-kick to Birmingham.
At least he correctly disallowed a McFadden effort for handball. Atrademark Bolton free kick broke the deadlock, as Kevin Davies buried aclassic header from Paul Robinson's delivery.
Awayday Blues: Birmingham James McFadden (right) bundled the ball home, but was outshone by Ivan Klasnic
MATCH FACTS BOLTON WANDERERS (4-4-2): Jaaskelainen 7; Steinsson 7, Cahill 8, Knight 7, Robinson 7; Weiss 6 (Lee 66min, 6), Wilshere 7 (Gardner 90), Muamba 7, Taylor 5 (Holden 66, 6); Davies 8, Klasnic 7.
Booked: Steinsson, Klasnic.
BIRMINGHAM CITY (4-4-2): Hart 7; Carr 6, Johnson 7, Ridgewell 6, Vignal 6; Larsson 6 (Benitez 66, 6), Ferguson 7,Bowyer 6, McFadden 7; Jerome 6, Michel 5 (Fahey 74, 6).
Booked: Ridgewell, Larsson, McFadden, Johnson, Bowyer.
Man of the match: Gary Cahill.
Referee: Kevin Friend.
In the second half, Vladimir Weiss crossed for Ivan Klasnic tostylishly side-foot his eighth of goal of the campaign. Friend thenpunished Jussi Jaaskelainen for a legal-looking punched clearance.
The keeper blocked Benitez's kick and parried Lee Bowyer's point-blank follow-up but McFadden bundled in.
'We came in knowing it would be a tough ask, but we have galvanisedthe players to show their qualities,' said Coyle, who entered a WorldCup plea for Gary Cahill.
Birmingham boss Alex McLeish said: 'We're still pinching ourselvesto be one of the low spenders and finish ninth. Now we've got to proveourselves again next season.'
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