Tennis: Medvedev makes all the right manoeuvres: Young Ukrainian underlines his potential as Edberg is frustrated again in his quest for a first French Open title

ON WOMEN'S semi-finals day here at the French Open, Steffi Graf and Mary Joe Fernandez had to share the honours with an impressive young man. Andrei Medvedev's victory against Stefan Edberg in a quarter-final match carried over because of rain the previous night was confirmation that here is a player of outstanding potential.

The 18-year-old Ukrainian won, 6-0, 6-7, 7-5, 6-4, unleashing an impressive array of shots to frustrate Edberg's quest for the one Grand Slam title he requires to complete his set. Wimbledon's lawns may prove too fast for Medvedev's predominantly baseline style, but he has the talent and confidence to test the best on concrete and clay.

Edberg appeared to have recovered from Wednesday's nightmare of taking only seven points in the opening set, which he lost in 17 minutes. When the match recommenced yesterday, at 5-5, he was worked steadily to the tie-break, which he won 7-3, taking advantage of two backhand errors by his opponent by driving one of his speciality backhands down the line.

From that point, Medvedev regained control, repeatedly drawing his opponent to the net and passing him. On eight occasions Edberg was left gasping as perfectly timed lobs glided over his racket. The Swede's own overhead shots were not so accurate, the three he misdirected when broken in the ninth game of the fourth set presenting Medvedev with the opportunity to close the match.

'I played some good tennis here and was on the right track, but Medvedev stopped me,' Edberg said. 'I think he actually has a chance to win it. I beat him in Monte Carlo, obviously under different conditions, but he is hitting the ball well, he is moving well on the court and he looks very strong.'

Jim Courier has dominated on the clay here at Roland Garros for the past two years, and the prospect of a final on Sunday between the defending champion and Medvedev is one to savour.

Two other players would dispute that, and in the semi-finals today Courier must overcome Richard Krajicek, and Medvedev will have to subdue his friend Sergi Bruguera. Courier is the only one with experience of a Grand Slam singles semi-final.

Medvedev has defeated Bruguera in their previous three matches, but he is not the type to underestimate opponents. 'Stefan was getting too close to the net in his previous matches, and I knew that without lobs I had no chance to pass him,' he said. 'The styles are completely different, and Sergi probably has 10 times more speed than Stefan.'

The Ukrainian promptly booked a practice court to prepare for the contrasting challenge of duelling with a fellow baseliner. Did he not fear that he would tire himself out? 'There is no word 'tired' in the semi- finals of a Grand Slam,' he said.

The women were not completely overshadowed. Though Graf's return to No 1 in the world in place of the injured Monica Seles with a 6-1, 6-1 win against her young compatriot, Anke Huber, was a routine exercise, Fernandez continued to astonish.

Having recovered from 1-6, 1-5 and saved five match points against Gabriela Sabatini, the third seed, in the quarter-finals, the Amercan advanced to meet Graf by defeating Arantxa Sanchez Vicario, the second seed,

6-2, 6-2. Not only did the Spaniard go into the contest as the most consistent winner on the tour this year, but she had defeated Fernandez in six of their previous seven matches. The one exception was Fernandez's success in the Wimbledon quarter-finals two years ago.

Fernandez missed her high school graduation ceremony in Miami to play here in 1989, when she lost to Sanchez Vicario in the quarter-finals. Yesterday she had the mobility and concentration to out-rally the best retriever in the women's game.

The American has yet to graduate as a Grand Slam champion, twice having been runner-up at the Australian Open, to Graf in 1990 and to Seles last year. Her record against Graf is not one to brag about.

She has lost to the Wimbledon champion in each of their 10 previous matches, though she did finally manage to win a set against her in their last contest, on clay in Berlin. 'I will have to play more aggressively and go for more,' Fernandez said. If she does, Graf will have to work much harder than she did for 48 minutes yesterday.

FRENCH OPEN (Paris) MEN'S SINGLES Quarter- finals: A MEDVEDEV (Ukr) bt S EDBERG (Swe) 6-0 6-7 7-5 6-4.

DOUBLES Semi-finals: L Jensen and M Jensen (US) bt S Edberg (Swe) and P Korda (Cz Rep) 7-6 6-1; M Gollner and D Prinosil (Ger) bt T WOODBRIDGE and M WOODFORDE (Aus) 7-6 6-2.

WOMEN'S SINGLES Semi-finals: S GRAF (Ger) bt A HUBER (Ger) 6-1 6-1; M J FERNANDEZ (US) bt A SANCHEZ VICARIO (Sp) 6-2 6-2.

DOUBLES Quarter-finals: L NEILAND (Lat) and J NOVOTNA (Cz Rep) bt K Maleeva (Bul) and N Tauziat (Fr) 6-4 7-6; G FERNANDEZ (US) and N ZVEREVA (Bel) bt K ADAMS (US) and M BOLLEGRAF (Neth) 6-4 3-6 7-5; S Cecchini (It) and P Tarabini (Arg) bt L McNEIL (US) and R Stubbs (Aus) 6-3 4-6 6-3.

MIXED DOUBLES Quarter-final: B Schultz (Neth) and M Jensen (US) bt G FERNANDEZ (US) and T WOODBRIDGE (Aus) 6-3 6-2.