World No.1 Andy Murray was given a good workout against Feliciano Lopez as he booked a place in the quarter-finals of the Barcelona Open with a hard-earned 6-4 6-4 win.

Murray entered the Spanish tournament to build up match time as he continued his recovery from an elbow injury but the 29-year-old Scot had been given a bye through to the second round and then saw Australian Bernard Tomic pull out of their scheduled contest on Wednesday because of a back problem.

But Murray eventually got the chance of another workout on clay when taking on Spaniard Lopez, who produced stubborn resistance before the top seed eventually produced the required response to progress into the last eight where he will meet either Albert Ramos-Vinolas or Roberto Bautista-Agut.

The opening set went with serve until Murray finally made the breakthrough in game eight to lead 5-3.

However, veteran Lopez, the world number 40, refused to be brushed aside easily, saving four set points after being 40-15 down before then breaking back himself.

Murray, though, regrouped and forced an immediate break chance in game 10, which Lopez saved with an ace before the British number one took his next opportunity after an hour on court.

Rather than fading, 35-year-old Lopez responded as he forced four break chances against Murray’s serve in game three before the Scot recovered. Murray’s frustrations were threatening to boil over as he squandered some five break opportunities against Lopez who levelled at 2-2.

However, Murray slowly started to deliver on his serve after moving 4-3 ahead and then to within touching distance of victory at 5-4 following successive love games.

The world No.1 then kept the pressure on Lopez, and took his second match point chance following a wide back-hand return from the Spaniard.

Meanwhile, Maria Sharapova declared herself “way above” responding to Eugenie Bouchard after recording the second win of her comeback to reach the quarter-finals of the Porsche Grand Prix in Stuttgart.

After a nervy start and ultimately comfortable win against Roberta Vinci in the first round on Wednesday, Sharapova stepped up a level to beat fellow Russian Ekaterina Makarova 7-5 6-1.

It came after world No.59 Bouchard said Sharapova, returning from a 15-month doping ban, was “a cheater” and that “a cheater in any sport should not be allowed to play again”.

Bouchard added: “She’s not someone I can say I look up to any more”
Asked by the media about the comments, Sharapova said: “I don’t have anything to say – I am way above that.”

On the court, the five-time grand slam champion generated huge power off her ground strokes from the off and wore down dogged Makarova over an hour and 19 minutes.

Both women held serve comfortably throughout most of the first set, with the first sign of alarm coming when Sharapova trailed 0-30 at 4-4.

But she dug in to hold serve, and then enjoyed a real stroke of fortune when Makarova pulled a backhand wide on break point at 5-5 with Sharapova helpless.

It cost her dearly as the former world number one broke in the next game to take the set.

Makarova, who had lost all of her six previous matches against Sharapova, never seemed to recover and the second set was one-way traffic.

The only slight concern was a growing proliferation of double faults from Sharapova, a weakness since severe shoulder problems earlier in her career.

But the seven doubles were outweighed by nine aces, the last of them on her first match point.

The draw has been kind to Sharapova and she will face another unseeded player in the quarter-finals in Estonia’s Anett Kontaveit.

The world number 72 is in great form, though, having reached the final of her last tournament in Switzerland before upsetting French Open champion Garbine Muguruza in the second round in Stuttgart.

Sharapova’s two victories have already ensured she will be back in the top 400 in the rankings on Monday, edging her closer to earning direct entry for Wimbledon.

The Russian has two more tournaments in Madrid and Rome in which to secure enough points, while reaching the final in Stuttgart would earn her entry into French Open qualifying without the need for a wild card.

Speaking in an on-court interview shown on BT Sport, the 30-year-old said: “Being the second match and playing yesterday and getting all the emotions out, I feel I settled down a little bit today and I was able to focus on my game. I executed a great plan.

“Practice is so different. You can prepare the best you can and when go out you just have to trust it. It was definitely great to come out and play matches and being in the quarter-finals here again is quite special.”