After bowing out of the Champions League in midweek, the San Siro outfit suffered a major setback in their hopes of qualifying for next season's tournament
The Argentine saw his dreadfully weak spot-kick saved by Andrea Consigli after just 21 minutes of play and the Nerazzurri never looked remotely like scoring thereafter as there two-game winning streak in all competitions came to an abrupt end.
Shorn of the services of Wesley Sneijder through injury, Inter looked utterly devoid of any creativity throughout. However, they were presented with a gilt-edged opportunity to open the scoring 21 minutes in when referee Gabriele Gava pointed to the spot after Thomas Manfredini had tangled with Giampaolo Pazzini in the area.
Pazzini had converted a penalty after coming on as a replacement in the midweek Champions League clash with Marseille but it was strike partner Milito who was entrusted with the responsibility of beating Andrea Consigli from 12 yards out.
The Argentine failed dismally in that regard, with his horribly tame side-footed effort easily pushed around the post by the Atalanta goalkeeper.
Samuel then went close to breaking the deadlock with a header from the corner which followed Milito’s miss but Consigli did well to gather at the second attempt and, in truth, Inter rarely threatened for the remainder of the half as they were restricted to pot-shots from distance from the likes of Joel Obi.
Atalanta offered little by way of attacking threat themselves, a well-struck strike from Cristian Raimondi which flew just wide their only shot on goal during the opening 45 minutes.
However, the visitors grew in confidence as the game wore on and, in truth, they looked the side more likely to break the deadlock in the second period.
Indeed, Manolo Gabbiadini made a huge difference to the Atalanta attack when he replaced the injured Guido Marilungo nine minutes into the second half.
The Italy Under-21 international drew a wonderful save out of the previously inactive Julio Cesar with a terrific header shortly after his introduction before then being criminally denied a penalty when he was felled by Lucio in the area with 11 minutes remaining.
As it was, though, Atalanta were forced to settle for a draw which edged them ever closer to safety but which was of little use to Champions League-chasing Inter, who remain seventh in the standings.