Dagenham & Redbridge.....2
Tranmere missed the chance to close the gap with league leaders Lincoln and were instead leap-frogged by opponents Dagenham as the Londoners left Prenton Park with all three points.
Goals from Corey Whitely and Oliver Hawkins did for Rovers, who are yet to win a league game in 2017 and are allowing their prospects of automatic promotion to rapidly diminish.
With Ritchie Sutton suspended following his dismissal against South Park, there was a recall for Michael Ihiekwe in the centre of defence.
James Wallace and top scorer Andy Cook also returned to the starting line-up at the expense of Lois Maynard and James Norwood.
After a quiet start, Andy Mangan found the net for Rovers in the 12th minute but was correctly ruled offside.
The Daggers had a good chance just before the quarter of an hour mark when Oliver Hawkins met a Luke Guttridge cross at the near post but could only steer the ball wide.
The visitors took the lead somewhat fortuitously in the 25th minute when a misplaced cross from Corey Whitely caught out Scott Davies and sailed into the top corner of the net.
A free kick from Frankie Raymond curled wide of the goal five minutes later as the East Londoners took command of the contest.
Tranmere were looking second best to everything but five minutes before the break Steve Jennings broke up play and released Cook. He was foiled by Jo Widdowson but won it back to set up Wallace, who saw his low shot saved by Elliot Justham.
Ben Tollitt was introduced for Jake Kirby at half time but things quickly went from bad to worse for Rovers when Dagenham doubled their lead just three minutes after the break.
Hawkins picked the ball up deep the Rovers half and made space for himself before drilling the ball past Davies.
Tranmere responded with Mangan glancing a free kick from Jeff Hughes onto the top of the crossbar.
Dagenham were only denied a third when – from a corner – a Hawkins header was cleared off the line by Jennings.
In need of more firepower Mellon brought James Norwood on for captain Jennings, deploying a genuine three-pronged attack.
Rovers immediately provided a greater threat, with the Daggers resorting to cynical tactics to thwart their advances, collecting cautions for Craig Robson and Shaun Donnellan in the process.
A shot from Cook was blocked before Hughes cut inside and saw his curling effort held, as Tranmere piled on the pressure.
A narrow left foot drive from Norwood was well saved by Justham before Tollitt shanked a half volley well over the bar with 10 minutes remaining.
Cole Stockton was hurled on for Mangan on 82 minutes, as Rovers went gung-ho.
The substitute saw a close range header cleared off the line following a Hughes corner, with seemingly no way through for the hosts.
Tollitt curled a free kick over the bar in injury time, but that was as good as it got for Rovers, who must accept that they were second best to their southern rivals and have to quickly halt the current slide if they are to keep pace with the other promotion hopefuls.
Manager Micky Mellon summed the game up: "If you could measure it you would probably say that we were 10% off all over the pitch.
“When we got into crossing areas, the crossing wasn’t good enough. When we did get it in, the movement wasn’t good enough. It’s just looked like we were slightly off all over.
“We’re not making excuses. We weren’t good enough to carve Dagenham open today. Their goals came at times where it seemed to affect us, which it will do when you’re looking for a lift.
“They’ll never let us down for effort, but in terms of that little 10%, it was missing from everybody today and it’s affected us.”
The result left Rovers in fourth place in the National League. They travel to face Woking on Tuesday evening. Kick-off is at 7.45pm.
Tranmere Rovers 0
Dagenham & Redbridge 2, Whitely 25, Hawkins 48
Half time: 0-1
Star man: James Norwood (Tranmere striker)
Tranmere (4-3-3): Davies (player rating) 6; Vaughan 5, Ihiekwe 6, McNulty 6, Ridehalgh 6; Wallace 6, Hughes 6, S Jennings 6 (Norwood 60, 7); Kirby 5 (Tollitt 46, 6), Cook 6, Mangan 5 (Stockton 82, 6).
Subs not used: Turner, Maynard
Dagenham (4-4-2): Justham (player rating) 7, Sheppard 6 (Doe 90, NA), Donnellan 7, Robson 7, Widdowson 6; Whitely 7 (Howell 70, 6), Baucaud 6, Raymond 7, Okinabirhie 6 (Maguire-Drew 83, 6); Guttridge 6, Hawkins 7.
Subs not used: Cousins, Benson