Debutant Luis Boa Morte failed to inspire new club Chesterfield to victory as Dagenham earned their first away win of the League Two season.
Ex-Arsenal and Fulham winger Boa Morte, who joined the club on Wednesday, played 90 minutes for the Spireites.
But he was upstaged by Sam Williams, who put the Daggers ahead with a low drive before curling in the winner.
Jack Lester had cancelled Williams's opener out, turning in Craig Westcarr's shot for his fifth of the season.
Boa Morte was denied a debut goal - and an equaliser - when visiting keeper Chris Lewington rushed out to block his 67th-minute shot.
VIEWS FROM THE DRESSING ROOM
Chesterfield caretaker manager Tommy Wright told BBC Radio Sheffield:
"The first half wasn't good enough, that's for sure. We lacked energy.
"We changed the system and I'll take responsibility for that, it didn't really work.
"I thought it would suit the players, but we changed it at half time and we looked better in the second half.
"We got back in it, a good goal for Jack (Lester) and we created one or two chances and we looked better in the second half."
Live Text Commentary
Jack Lester is ruled offside. Chris Lewington takes the free kick.89:39
Sam Williams concedes a free kick for a foul on Drew Talbot. Richard O'Donnell takes the free kick.88:30
Unfair challenge on Sam Williams by Drew Talbot results in a free kick. Free kick taken by Femi Ilesanmi.87:44
Corner from right by-line taken by Luis Boa Morte.84:29
Femi Ilesanmi fouled by Tendayi Darikwa, the ref awards a free kick. Free kick taken by Femi Ilesanmi.83:41
Corner taken by Matthew Saunders from the right by-line, clearance by Sam Hird.83:00
Foul by Liam Ridehalgh on Michael Spillane, free kick awarded. Free kick taken by Chris Lewington.80:41 Substitution
Substitution (Chesterfield) makes a substitution, with Scott Boden coming on for Craig Westcarr.77:37
Outswinging corner taken from the right by-line by Craig Westcarr. Outswinging corner taken from the right by-line by Medy Elito.77:00
Matthew Saunders takes a shot.75:43
The referee blows for offside. Direct free kick taken by Chris Lewington.74:46
Femi Ilesanmi gives away a free kick for an unfair challenge on Tendayi Darikwa. Craig Westcarr takes the direct free kick.72:16 Substitution
Substitution Mark Randall joins the action as a substitute, replacing Sam Togwell.71:58 Full time
Full Time The referee brings the game to a close.69:32
The referee blows for offside against Craig Westcarr. Chris Lewington takes the direct free kick.67:46
The assistant referee signals for offside against Sam Williams. Drew Talbot takes the direct free kick.66:50
Luis Boa Morte takes a shot.62:51
The ball is delivered by Jack Lester, Scott Doe manages to make a clearance.61:33 Substitution
Substitution Tendayi Darikwa on for Neal Trotman.56:40
Femi Ilesanmi provided the assist for the goal.
Goal! - Sam Williams - Chesterfld 1 - 2 Dag & Red Sam Williams gets on the score sheet with a goal from the edge of the penalty area to the top right corner of the goal. Chesterfield 1-2 Dag & Red.54:09
Craig Westcarr provided the assist for the goal.54:09 Goal scored
Goal! - Jack Lester - Chesterfld 1 - 1 Dag & Red A goal is scored by Jack Lester from inside the penalty area low into the middle of the goal. Chesterfield 1-1 Dag & Red.53:28
Corner taken left-footed by Luis Boa Morte from the right by-line, clearance made by Dwight Gayle.50:27
Corner taken left-footed by Craig Westcarr, clearance made by Michael Spillane.48:00
Corner taken by Matthew Saunders, Terrell Forbes manages to make a clearance.45:01
The referee blows his whistle to start the second half.45:00 +3:12 Half time
Half Time The referee blows for half time.41:25
Assist on the goal came from Dwight Gayle.41:25 Goal scored
Goal! - Sam Williams - Chesterfld 0 - 1 Dag & Red A goal is scored by Sam Williams from outside the penalty box to the bottom right corner of the goal. Chesterfield 0-1 Dag & Red.38:32
Craig Westcarr fouled by Medy Elito, the ref awards a free kick. Richard O'Donnell takes the free kick.35:38
Chris Atkinson crosses the ball, clearance by Luke Wilkinson.33:58
Outswinging corner taken by Matthew Saunders from the right by-line.33:21
Liam Ridehalgh crosses the ball, Luke Howell manages to make a clearance.31:41
Jack Lester is caught offside. Chris Lewington takes the free kick.31:19
Free kick awarded for a foul by Sam Williams on Sam Togwell. Direct free kick taken by Sam Hird.28:52
Unfair challenge on Luis Boa Morte by Michael Spillane results in a free kick. Terrell Forbes restarts play with the free kick.28:18
Corner taken by Matthew Saunders, clearance made by Luis Boa Morte.26:39
Effort from 25 yards by Dwight Gayle. Blocked by Richard O'Donnell.25:52
Luke Wilkinson challenges Jack Lester unfairly and gives away a free kick. Sam Hird takes the direct free kick.24:12 Booking
Booking Luke Wilkinson goes into the book for unsporting behaviour.22:56
Corner taken by Matthew Saunders, clearance made by Neal Trotman.22:00
Sam Togwell gives away a free kick for an unfair challenge on Luke Howell. Chris Lewington takes the free kick.21:23
The ball is swung over by Abu Ogogo.18:50
Corner from the right by-line taken by Craig Westcarr, clearance made by Scott Doe. Inswinging corner taken by Craig Westcarr, clearance by Femi Ilesanmi.18:01
Free kick awarded for a foul by Femi Ilesanmi on Jack Lester. Direct free kick taken by Drew Talbot.14:25
Free kick awarded for a foul by Sam Williams on Drew Talbot. Free kick taken by Richard O'Donnell.12:48
Free kick awarded for an unfair challenge on Luke Wilkinson by Jack Lester. Chris Lewington takes the direct free kick.11:50
Neal Trotman fouled by Sam Williams, the ref awards a free kick. Direct free kick taken by Richard O'Donnell.11:36
Scott Doe fouled by Jack Lester, the ref awards a free kick. Chris Lewington restarts play with the free kick.9:51
Unfair challenge on Matthew Saunders by Chris Atkinson results in a free kick. Michael Spillane takes the direct free kick.7:50
Unfair challenge on Drew Talbot by Dwight Gayle results in a free kick. Free kick taken by Richard O'Donnell.5:20
The official flags Jack Lester offside. Scott Doe takes the free kick.4:07
Luis Boa Morte takes the inswinging corner,1:58
Inswinging corner taken by Luis Boa Morte.1:02
Luis Boa Morte takes the inswinging corner, clearance by Scott Doe.0:00
The referee gets the match started.
Live data and text provided by our data suppliers