Scottish superstar Andy Murray was pushed hard in his opening clay court match of the season.
The world number three – top seeded at the German event – faced qualifier Mischa Zverev, and was forced to save six break points in his 6-2 6-2 victory.
“I thought I started off the match well today and played pretty well,” said Murray.
The Scot, who is back in action for the first time since getting married earlier this month, has never before made the final of a tournament on clay but is hoping to change that this week.
In the last eight he will take on Lukas Rosol.
Murray hoping to improve clay game in Munich
Andy Murray will be hoping for an improvement in his clay court form as he begins his build-up to the French Open.
“It was a good match today and I am looking forward to tomorrow,” said Dimitrov.
“I played a solid, structured game and it was enough for me to win today.”