April 30 (Reuters) - Belgium's Alexander Blockx continued his breakthrough run at the Madrid Open on Thursday, upsetting defending champion Casper Ruud 6-4 6-4 to reach the semi-finals of a Masters 1000 event for the first time in his career.
Blockx had never won an ATP Tour-level match on clay before this month but he has thrived in Madrid, earlier knocking out third seed Felix Auger-Aliassime en route to the last four.
Blockx wrapped up the victory in 96 minutes to become the fourth-lowest-ranked player to reach the semi-finals in the tournament's history. The world number 69 showed few signs of nerves as he dismantled Ruud with aggressive baseline play and solid serving.
"I'm proud of how I've played these past couple of matches. I think the conditions suit me well here," Blockx, 21, said in his on-court interview.
"I feel like it's clay which is slow, so I have time to settle and hit my shots, go for my shots.
"At the same time, it's quite fast with the altitude and the heat sometimes. I think it's the perfect combination for me."
Blockx will next face either second seed and two-time champion Alexander Zverev or 10th seed Flavio Cobolli, who meet later on Thursday.
(Reporting by Karan Prashant Saxena in BengaluruEditing by Christian Radnedge)
