The two players are no strangers, having previously met two weeks ago during a Billie Jean King Cup tie in Prague. Martincova was the Brit's first ever opponent on clay, with the teenager going on to seal a 7-5 7-5 victory.
On this occasion, the Raducanu was similarly clinical as she powered to a 7-6 6-0 win at the Caja Magica.
Raducanu was forced to show resilience in the opening set as she battled back from 5-2 down, saved two set points and rallied to win the tiebreak. The second set was a lot more comfortable as the 19-year-old put on a clinic to book her place in the second round of the Madrid Open.
Speaking during her on-court interview, Raducanu said: "It was a tricky first set. I think it's always tough playing on a brand new court, so it took me a little bit to adjust to my surroundings. "And, of course, if you're low or lacking in your own game then an opponent at this level is going to take advantage of that. I'm just glad that I stuck through the first set and then definitely relaxed in the second.
"I love Madrid, I've been out once, it's such a cool vibe. I'm looking forward and hopefully I get to spend some more days here." The Brit made headlines this week after spitting from coach Torben Beltz despite an encouraging display in Stuttgart. Raducanu is currently supported by Lawn Tennis Association's head of women's tennis, Ian Bates. The US Open champion will now turn her focus to Ukrainian teenager Marta Kostyuk in the second round, who beat Denmark's Clara Tauson in straight sets. The pair previously met in Romania last October, with the Kostyuk going on to win 6-2 6-1 in exactly 60 minutes.
Raducanu told wtatennis.com: "All throughout juniors she was always the favourite when we played. She was considered much better. It's a funny one. When we played last year she played very good, but also I wasn't very well that day. So it'll be an interesting match-up."
Elsewhere, Naomi Osaka picked up an impressive 6-3 6-1 victory over Anastasia Potapova. World number five Maria Sakkari was forced to produce a comeback against Madison Keyes as she prevailed 6-7 6-3 6-4 to progress. There were also high-profile casualties, as Sloane Stephens and Petra Kvitova crashed out following 2-0 defeats to Anhelina Kalinina and Jil Belen Teichmann.
The article Emma Raducanu serves up second-set bagel to set up Madrid Open clash with Marta Kostyuk appeared first on Planetsport.com.