Eastbourne, England, 21 June 2012 | AAP

Bernard Tomic has marked his Wimbledon promotion with a disappointing three-set loss to Italian Fabio Fognini in his opening match at the Eastbourne grasscourt event.

After enjoying a first-round bye, the fourth-seeded Tomic slumped to a 4-6 6-3 7-5 defeat to the world No.61, his final preparation before the grasscourt major starts on Monday.

Tomic’s loss from 5-3 up in the deciding set came just hours after Wimbledon officials elevated the 19-year-old to 20th seed despite his ranking of No.27 in the world.

The teenager was rewarded for last year becoming the youngest men’s quarterfinalist at the All England Club since Boris Becker in 1986 and the promotion ensures Tomic will avoid running into a top-eight seed until at least the fourth round.

The Australian is sure to be thankful after snatching defeat from the jaws of victory against the lowly claycourt specialist on Wednesday.

Tomic looked to be cruising at a set up. But after being untroubled on serve, he squandered a bagful of break-point chances and then dropped serve from 40-love up in the fifth game of the second set.

The costly slip-up allowed the 2011 French Open quarterfinalist to take the set and force a decider.

Then just as Tomic looked to have regrouped and done enough after breaking Fognini for a 3-0 lead in the third set, he faltered trying to serve out the match.

From 5-2 up, he lost five consecutive games – and the match – after one hour and 53 minutes.

Tomic’s exit leaves Marinko Matosevic as the only Australian left in tournament action five days out from Wimbledon.

Matosevic plays Belgian Steve Darcis on Thursday for a place in the semifinals after upsetting French top seed Richard Gasquet in the second round.