Man City claims first road victory
The opening goal came in the 16th minute when Fernandinho's slide-rule pass was allowed to run by Alvaro Negredo, putting the West Ham defence on their heels and giving Aguero the opportunity to ghost into the box and finish with aplomb beyond Jussi Jaaskelainen.
The Argentina international then accepted a gift-wrapped second from the home side early in the second half as he was left unmarked eight yards out to power a header in at the near post from David Silva's free-kick despite the best efforts of Jaaskelainen.
West Ham responded well and enjoyed their best period of the match, which culminated in an improvised response as Stewart Downing's header back across the box was flicked on by Ravel Morrison for Ricardo Vaz to fire an overhead kick into Joe Hart's bottom corner in the 58th minute.
But City's first away win in the Premier League this season was sealed with 10 minutes remaining as Aguero turned provider, setting up Silva with a neat back-heel to curl a powerful left-foot shot across Jaaskelainen to halt any hopes of a comeback from the home side.