Defending champion Spain got off to an inauspicious start in the second phase of the EuroBasket 2013 championships in Slovenia, losing 79-75 on Thursday to Greece.

The Spaniards are now left with no margin for error and must win their upcoming games with Finland and Italy.

Spain seized the early lead thanks to a bucket by center Marc Gasol and a 3-pointer by Jose Calderon, holding a 26-16 advantage at the end of the first quarter despite Gasol's early foul trouble.

Spanish guards Ricky Rubio and Sergio Llull also did a good job in the early going on Greek star Vassilis Spanoulis, holding him to just three points.

The momentum changed quickly in the second quarter, however, with Gasol on the bench with three fouls.

Spanish coach Juan Antonio Orenga opted for a zone to shore up his interior defense, but Spanoulis took advantage to score five consecutive points and Greece later took a 41-38 halftime lead.

Gasol came back on the floor in the third quarter and helped spur Spain to a 57-52 lead going into the fourth quarter, but another Greek surge brought the score to 64-64 with four minutes left.

Spanish forward Victor Claver picked up his fifth personal foul late in the game, while Greece's Ioannis Bourousis scored a couple of key buckets to make the score 68-64 and put Spain on the brink of defeat.

Spanoulis, the Greek squad's floor general, then controlled play down the stretch and the Spanish players were left to contemplate how an apparent victory had slipped through their fingers. EFE