The talented Latvian was characteristically erratic, looking off his game in the first set before finding his rhythm in the second to storm through for a creditable victory.
There were no such woes for eighth seed Igor Kunitsyn, who beat Fernando Gonzalez of Chile in straight sets, 6-4 6-3.
Former world number two Tommy Haas suffered a 6-3 6-2 defeat to Bulgaria's Grigor Dimitrov, a player currently ranked at 57, over 500 places above the German.
James Blake gave the home fans something to cheer with a 6-2 6-3 win over Michael Berrer of Germany, while Luxembourg's Gilles Muller beat another American, wildcard Steve Johnson, 2-6 6-3 6-4 to set up a second-round match with top seed Mardy Fish.
Elsewhere there were wins for Ryan Harrison, Alex Bogomolov Jr, Alejandro Falla and Daniel Kosakowski.