Halle, Germany, 16 June 2015 | AAP

Bernard Tomic has been bundled out of the first round of the Gerry Weber Open after a straight sets loss to Steve Johnson.

Seventh seeded Tomic, who has risen to No.24 in the world after a consistent first half of the season, was favoured to oust the American ranked 29 spots below him.

But Johnson enjoyed a relatively comfortable 6-3 7-6(4) win.

Johnson snatched a break to take the first set and quickly found himself with another to have a 2-0 lead in the second.

Tomic stepped up to get the clash back on serve but Johnson needed just one match point in the tie breaker to seal the result.

The Australian had enjoyed a better last week in Stuttgart, reaching the quarterfinals before being beaten by eventual champion Rafael Nadal in a tight three-set match.