Verkerk is playing in his first French Open Photos from Roland Garros

Big-serving Verkerk, who is playing for the first time at Roland Garros, beat the fourth seed 6-3 6-4 5-7 4-6 8-6 in a battle lasting nearly four hours.

The 24-year-old, who fired down 27 aces in the contest, had been two sets up before allowing Spaniard Moya back into the match.

But the Dutchman kept his nerve and finally clinched victory with another booming first serve, celebrating with a trademark pumped fist and collapsing on the clay in disbelief.

It's amazing, I don't know how it happened Martin Verkerk

Moya struggled to cope with the pace of Verkerk's serve and soon found himself down two sets.

He diced with defeat at the end of the third but took advantage as Verkerk's serve temporarily lost its way.

Moya continued to press in the fourth and after saving a break point in the seventh game, Verkerk finally caved in in his next service game to hand the set to the Spaniard.

Watch day nine highlights

Then it seemed that Moya had grasped the initiative but the Dutchman, increasingly pumped up in the fifth set, showed real determination to fight back.

He broke Moya in the 13th game and then produced four unreturnable first serves to clinch a famous victory.

Verkerk, who beat 11th seed Rainer Schuettler in straight sets in the previous round, is now just one match away from a Grand Slam final.

He will play Guillermo Coria, conqueror of Andre Agassi, in the last four.