Andujar, ranked 93rd in the world, battled Zemlja, ranked 52nd, for a 6-7 (8-10), 7-6 (7-3), 6-2, victory. The match, the last on Monday's 10-match schedule, took more than 2 1/2 hours.
After Andujar and Zemlja traded tight tiebreaker wins, Andujar took the first five games of the third set. He ended up winning more than 60 percent of the points in the match and closed the win with his fifth break of the day.
Pablo Carreno-Busta, a wild-card entrant, used a win in a third-set tiebreaker to advance over Robin Haase, 6-1, 2-6, 7-6 (7-5). Ivan Dodig rallied for his three-set win, stopped Aljaz Bedene 6-7 (6-8), 6-3, 6-2.
Also qualifier Guillermo Olaso took out Gerard Granollers, another wild-card entry, 6-4, 1-6, 6-4.
The rest of Monday's matches were decision in straight sets, including Andrey Kuznetsov's 6-1, 6-3 romp over Igor Sijsling in 45 minutes in which he lost only seven points in eight games serving. Also Nikolay Davydenko beat Roberto Carballes Baena 6-1, 6-4 with six breaks.
Notable deaths of 2014 [PHOTOS]
Michael Sam cut from the Dallas Cowboys