Andy Murray fights through opening match in Munich

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.

At ATP Istanbul Grigor Dimitrov booked a spot in the quarter-finals with a 6-3 6-2 win over Andrey Golubev.

"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."

Dominic Thiem (Austria) beat 8-Fabio Fognini (Italy) 6-3 6-0

1-Andy Murray (Britain) beat Mischa Zverev (Germany) 6-2 6-2

Gerald Melzer (Austria) beat Pablo Andujar (Spain) 4-1 (Andujar retired)

9-Lukas Rosol (Czech Republic) beat Sergiy Stakhovsky (Ukraine) 7-5 6-2

Ivan Dodig (Croatia) beat Dusan Lajovic (Serbia) 5-7 7-6(1) 6-4

2-Grigor Dimitrov (Bulgaria) beat Andrey Golubev (Kazakhstan) 6-3 6-2

Thomaz Bellucci (Brazil) beat Denis Istomin (Uzbekistan) 7-6(4) 6-3

3-Pablo Cuevas (Uruguay) beat Teymuraz Gabashvili (Russia) 4-6 6-4 6-4

Borna Coric (Croatia) beat Rui Machado (Portugal) 6-4 5-7 6-1

8-Gilles Muller (Luxembourg) beat Albert Montanes (Spain) 4-6 6-3 7-6(7)

Guillermo Garcia-Lopez (Spain) beat 2-Kevin Anderson (South Africa) 6-4 3-6 6-1

Pablo Carreno (Spain) beat David Vega (Spain) 6-1 6-2