LONDON: Roberto Bautista Agut reached his first Grand Slam semi-final by wearing down Argentine Guido Pella at Wimbledon on Wednesday to steal a march on his more decorated fellow Spaniard Rafa Nadal.

The understated 31-year-old Bautista Agut dropped his first set of the tournament but 26th seed Pella's gruelling campaign caught up with him as the number 23 seed won 7-5 6-4 3-6 6-3.

It was the first Wimbledon quarter-final not featuring a top-20 player since a Polish duel between Jerzy Janowicz and Lukasz Kubot in 2013 but for the Court One ticket holders it proved an enjoyable appetiser for twice champion Nadal's clash with American Sam Querrey on the same stretch of turf later.

Bautista Agut is a rugged and reliable performer in Grand Slams and a regular visitor to the third and fourth rounds.

This year has seen a breakthrough though and he reached his first quarter-final at the Australian Open.

Now he has gone one better and will become only the sixth Spaniard to contest a Wimbledon men's semi-final when he takes on top seed and defending champion Novak Djokovic.

Bautista Agut will not be daunted either, having twice beaten the Serb this year.

He squandered a 0-40 lead on Pella's serve in the fifth game of the first set with a double break on offer and was then dragged into a fierce baseline fight before breaking for a 6-5 lead and then serving out the opener.

Pella had spent six hours longer on court to reach his first Grand Slam quarter-final and looked weary as he dropped serve at the start of the second set -- that proving enough for Bautista Agut to move to within a set of victory.

The left-handed Argentine was not finished though and hit back with some dazzling tennis to snatch the third set.

However, the business-like Bautista Agut was relentless and jumped ahead in the fourth set before claiming victory when Pella looped a forehand over the baseline.