The Ibrox club struggled to beat their part-time rivals in a League One game at Station Park yesterday.
Ally McCoist's side needed a blunder by Forfar defender Darren Dods to score before half-time in the televised clash. And they had to defend frantically to scrape a 1-0 win against the team that dumped them out of the League Cup in August.
The narrow triumph put the Glasgow giants five points clear of nearest rivals Dunfermline and Stenhousemuir at the top of the division once again. However, with seven of their new signings in the starting line-up in Angus, the performance did not go down at all well with the Light Blues support.
Scotland left-back Wallace, however, has urged his side, who maintained their 100% league record, not to dwell on the poor display for too long.
Having been on the losing side in the painful 2-1 loss to Dick Campbell's side at Station Park two months ago, he was happy to get the victory.
And the defender wants Rangers to focus fully on producing a vastly improved showing against Stenhousemuir at Ibrox this Saturday.
He said: "The performance wasn't ideal obviously. We know that. But we got the three points and that is the most important thing on match day.
"The performances have been good so far this season. So obviously we will forget the performance, be happy with the three points and rectifying the result earlier in the season."
McCoist felt the strong winds which buffeted both sets of the players at Station Park had made it difficult for both teams to get to grips with the game.
The Gers gaffer also admitted the artificial pitch - the second one his side had played on in six days -had not been to his charges' liking.
Wallace, who needed to come off briefly in the second half to receive medical treatment after hurting himself on the 3G surface, was unsure why Rangers performed so poorly. But the 26-year-old feels getting the victory - his side's sixth in the league in the 2013/14 campaign - in a difficult away fixture was all that mattered.
And he remains confident the Gers can turn on the style once again when they host third-placed Stenhousemuir at Ibrox this weekend.
He said: "I'm not sure if the wind or the pitch affected us. We just didn't play at all like how we usually do or anywhere near how we are capable of playing.
"But we got the three points and that is the most important thing on the day. We will certainly look to try and improve the performance next week.
"We knew there would be difficult games, especially away from home, in this league this season despite what people were saying. We will just look to the next match now."