Welling lost ground in National League South on Saturday after a woeful display at home to East Thurrock.
It was a fourth home defeat of the season for Jamie Coyle's men, who had Connor Dymond sent-off in the second half.
A goal from ex-Welling man Reece Harris sent them on their way and despite a spirited response early in the second half, two goals from Sam Higgins confirmed Welling's fate.
Welling limped out of the FA Trophy against Weston on home turf last week and it prompted boss Jamie Coyle to make a number of changes.
Bradley Goldberg was the lone striker, supported by Joe Healy, while Ben Jefford returned at left-back and on-loan Maidstone midfielder Harry Phipps went into the starting line-up.
East Thurrock gave Welling two early warnings. Tom Richardson produced a neat exchange with Sam Higgins before his low left-foot shot was brilliantly turned away by on-loan Millwall keeper Ryan Sandford.
He came to Welling's rescue again two minutes later, denying Reece Harris, and he then produced two close-range saves from two Higgings headers.
It was no surprise when Harris put East Thurrock ahead on 33 minutes. Welling failed to clear their lines and the ball was worked back down the right-wing before Harris produced a crisp right-foot finish against his former club.
Welling's best moments came from Goldberg at the other end. One right-foot shot went just wide of the near post, an exchange with Christian Nanetti ended with East Thurrock keeper Harry Wright saving well, and then the keeper beat away Goldberg's left-foot shot.
The hosts had two free-kicks on the edge of the East Thurrock area just before half-time. But Welling were unable to seriously trouble Wright and they headed in at the break devoid of ideas.
The introduction of Tom Bradbrook at the interval gave Welling a proper out-ball up front. Nanetti shot at the keeper before Bradbrook headed over the former's corner.
Welling should have had a penalty seven minutes into the second half. Bradbrook was hauled to the ground when he seemed to certain to head in from close range but referee Alex Blake must have been unsighted.
Healy then tricked his way through a couple of challenges but was thwarted by a last-ditch tackle.
Welling continued to press and they should have been level on 58 minutes. Healy nodded down for Goldberg and when his right-foot shot was beaten away it fell perfectly for Archie Johnson at the far post. But Johnson, left with an open goal, somehow fluffed his lines and his right-foot effort went away from goal instead of towards it.
It was to prove a big miss. Welling were reduced to 10 men on 69 minutes when Dymond, needlessly booked after putting his hands on the referee to dispute the earlier penalty appeal, collected his second yellow card for a late challenge.
Higgins hit the woodwork from the resulting free-kick but he made no mistake a minute later, having too much strength to hold off Jack Parkinson before firing in low from the edge of the box.
East Thurrock added a third with eight minutes left when the classy Higgins produced a glorious right-foot 20-yard finish from the edge of the area which went in via the upright.
Welling: Sandford, Dymond, Jefford (E Phipps 76mins), Durojaiye, Coyle, Parkinson, Nanetti (Jebb 80mins), Healy, H Phipps (Bradbrook 46mins), Goldberg, Johnson. Subs not used: Gayle, Francis.
East Thurrock: Wright, Sammons, Sampayo, White, M Ekpiteta, Agyemang, C Ekpiteta (Honesty 68mins), Cornhill, Higgins, Harris, Richardson. Subs not used: Smith, Allen, Belho, Lidakevicius.