Colsaerts lost his opener to a South African for the second year running, going down 4 and 3 to Grace at Thracian Cliffs Golf & Beach Resort.
Grace had moved into a five-hole lead but Colsaerts fought back at the 10th and 12th to cut the lead to three with five holes to play.
But the Belgian bogeyed the 14th, allowing Grace to seal victory.
The loss is not fatal for Colsaerts, who can still qualify for the last 16 from the group format, having done so after losing his first two group matches last year, to Charl Schwartzel and Retief Goosen.
Sweden’s Carl Pettersson, who has rejoined the European Tour to try and make the Ryder Cup team, claimed a 4 and 3 victory over Denmark’s Thorbjørn Olesen.
Gonzalo Fernandez-Castano beat Jamie Donaldson on the 18th. Welshman Donaldson almost claimed a half after being four down with seven to play, but his birdie on the final hole was matched by the Spaniard.
Graeme McDowell, Francesco Molinari and Peter Hanson all won, but match-play specialist Ian Poulter was beaten 3 and 2 by Thongchai Jaidee.
- Sports & Recreation