Top seed and defending champion Paradorn Srichaphan suffered a surprise first round exit at the Stockholm Open when little-known Dutchman John Van Lottum beat him 7-5, 6-1 on Wednesday.

The Thai, 11th in the Champions Race, saw his slim chance of reaching the Masters in Houston next month recede further as Van Lottum outplayed him with clever tactics in their first meeting.

But the philosophical Paradorn said: "Actually, it's not really a goal for me to reach the Masters this year".

Van Lottum refused to be intimidated by Paradorn's more powerful shots and efficiently varied the pace of his own strokes throughout the match, provoking several unforced errors from the Thai.

"He played really well, he did almost nothing wrong, it was near perfect," Paradorn said of his opponent. "He put me under pressure all the time.

"If he keeps this form, I think he could reach maybe the semi-finals."

Van Lottum broke Paradorn to lead 6-5 and then kept his cool to come back from 0-40 on his serve to take the first set.

The Thai grew impatient in the second set as he went for winners but only made more errors and immediately lost his serve. He was broken twice more as Van Lottum wrapped up the victory.

"I didn't play badly in the beginning, we both played well at first," said Paradorn. "(In the second set) I lost my mentality, it felt like it was going to be tough to get back, plus he didn't lose his groundstrokes.

"It was a little different this year for me, there's really been a lot of pressure on me. I was the champion, so there were a lot of expectations."

SEEDS STUMBLE

Dutchman Raemon Sluiter and Swede Joachim Johansson also caused upsets by beating Chileans Nicolas Massu and Fernando Gonzalez, seeded third and fourth respectively.

Sluiter, a powerful server who plays double-handed on both sides, beat Massu 6-3 3-6 7-5 in a match that swung both ways.

Massu, coming off a fine week in Madrid where he reached the final, did not find his rhythm until the middle of the second set second set when he broke Sluiter to lead 4-2 and then held serve to take the match to a decider.

With Sluiter ahead 6-5 Massu suffered a net cord on his serve that gave the Dutchman the upper hand at 0-30. Sluiter took advantage and broke the Chilean to clinch the match.

"It was tough with two days rest coming from Madrid, but I gave one hundred percent," said Massu. "It really was a case of bad luck when I was broken (in the final game)."

"The court and the balls felt a little different from Madrid, there was nothing wrong with it, just a little different."

Johansson ousted Gonzalez 4-6, 6-4, 7-5 in his second-round match to delight the home crowd and became the second player through to the quarter-finals alongside American Mardy Fish, the fifth and highest seed remaining in the draw.

Johansson needed one hour and 35 minutes to get past the Chilean in what turned out to be a battle of the big servers. He hammered 28 aces past Gonzalez, who hit 21 himself.

Fish had defeated French qualifier Julien Benneteau 6-4, 6-4 earlier in the day.