World number one Andy Murray beat Tunisia's Malek Jaziri in straight sets at the Dubai Championships in his first match for five weeks.
Murray, 29, was playing for the first time since his fourth-round defeat at the Australian Open last month.
Jaziri, ranked 51st in the world, broke Murray's serve early on but the top seed recovered to win 6-4 6-1.
Britain's Dan Evans also reached the second round with a 6-2 6-3 victory over Germany's Dustin Brown.
Murray will face Spain's Guillermo Garcia-Lopez, who won their last meeting at Indian Wells in 2012, on Wednesday, while Evans takes on French fourth seed Gael Monfils.