Argentina were held to a 1-1 draw against Venezuela on Thursday in Lionel Messi's return to international duty in South America's World Cup qualifiers.
Captain Messi, 37, fully recovered from an injury sustained in the Copa America final against Colombia in July, was brilliant in setting up Otamendi on a drenched pitch to open the scoring 13 minutes after kick-off, which was delayed by half an hour due to heavy rain.
A fierce Venezuela equalised in the second half when Salomon Rondon's header from Yeferson Soteldo's pass beat goalkeeper Geronimo Rulli, who filled in for Emiliano 'Dibu' Martinez as he is serving a two-match ban for offensive behaviour.
Argentina remain top of the standings with 19 points and will face Bolivia on Tuesday, while Venezuela, who moved up to sixth on 11 points, visit Paraguay.