After narrowly losing the first set of the match that finished well past midnight after the programme was disrupted by rain, Ljubicic took a 3-1 lead in the second set and the contest appeared to be heading for a decider.
However, too many unforced errors enabled the 33-year old Pavel to break back twice and clinch a place in the second round.
Ljubicic is the second leading player to be eliminated in the first round, joining second seed Nikolay Davydenko of Russia on the sidelines.
Yesterday, four seeds -- four-times winner here Carlos Moya of Spain, his compatriot David Ferrer, Guillermo Canas of Argentina and Italy's Filippo Volandri -- secured their places in the second round.
Top seed and last year's runner-up Serb Novak Djokovic will face compatriot Viktor Troicki later today for a spot in the quarter-finals.
REUTERS BJR VV1523