Di Santo had been guilty of missing multiple chances before his goal, but it was worth the wait as his equaliser cancelled out a fabulous first half finish from Greece midfielder Giorgos Karagounis, who produced one of the rare moments of quality on display in the match.
Martin Jol will be frustrated at his side's lack of verve, particularly during the second half when they allowed Wigan back into the game without the visitors being forced to significantly improve.
The game pitched together two sides who had recently managed to end their respective slumps that had seen an alarming drop down the Premier League. Fulham had won one of their last 12 games which had seem them fall from sixth to 14th before winning 2-1 at West Brom, whilst Wigan's 3-0 away victory over Aston Villa came after seven losses in their last nine games.
Jol preferred Dimitar Berbatov in attack, leaving Hugo Rodallega on the bench against his former club. Roberto Martinez, meanwhile, found no place in the matchday squad for new signing Roger Espinoza, whilst on-loan Angelo Henriquez was on the bench and was not used.
Wigan started the brighter of the two teams and, after just five minutes, Di Santo was presented with the ball two yards out and somehow could only roll his attempt into Mark Schwarzer's hands. The Argentinian was flagged offside, but it was an incorrect decision that saved the striker's blushes.
Fulham then began to stamp their authority on possession and created a couple of openings, Mladen Petric twice firing over from outside the area as Bryan Ruiz dropped into midfield to allow the Croatian and Berbatov to roam up front.
Halfway through the first period, Fulham took the lead with the first piece of real creativity. Karagounis dropped his shoulder to beat James McArthur in midfield and then fired a shot from 25 yards that flew in off the left hand post to give Ali Al-Habsi no chance.
The goal seemed to invigorate Wigan, who began to enjoy more possession, but they were too wasteful in attacking areas. McArthur twice fired straight at Schwarzer, before Di Santo was guilty of an awful miss just before the break. The ball was fired across the six-yard box by Emmerson Boyce, but the forward somehow hit the ball comfortably over the bar on the half-volley.
During the second half, Fulham looked poor as they allowed Wigan back into the game and Schwarzer was forced into a world-class save from a deflected Shaun Maloney shot, as the Craven Cottage faithful began to grow uneasy.
Wigan grabbed a foothold in the match and their goal, when it finally came, was from Di Santo, who made amends for his first-half misses with a finish of real quality. Fulham defenders backed off and allowed him to shoot, and his shot arrowed into the top right-hand corner of Schwarzer's goal.
The last 20 minutes followed a similar pattern, with Wigan enjoying the ball and pushing for victory as the crowd began to audibly state their disapproval at the lacklustre fare being served up by their side.
A point was probably a fair result for both teams, but Roberto Martinez will certainly be the happier of the two bosses. For Jol, the presence of Ruiz, Berbatov and Petric in a side that continues to look blunt is becoming increasingly worrying.