MELBOURNE, Australia(AP) Yen-hsun Lu had barely walked off the court at Melbourne Park on Wednesday after one of his biggest career wins when his mobile phone started ringing.

I picked up the phone and my friends were calling to congratulate me,'' Lu said.I could tell they were all happy for me.''

His friends back in Taiwan had good reason to be excited.

Lu, whose previous biggest win was a first-round upset of Britain's Andy Murray at last year's Beijing Olympics, pulled off a marathon upset of 10th-seeded David Nalbandian in the second round at the Australian Open.

Lu beat the 2002 Wimbledon finalist 6-4, 5-7, 4-6, 6-4, 6-2 in a match just short of four hours, marking the first time in 12 Grand Slams that the 25-year-old Lu has advanced past the second round.

Lu persevered through a 10-minute final game when he fought off six break points, but he had a strategy - reverse psychology.

Everybody knows Nalbandian is one of the best backhand players,'' Lu said.So I thought he's ready for a forehand return. So I just changed my mind and went to his backhand all the time.

``I served six times to his backhand on break point and I won all the points.''

Lu said he had nothing to lose.

For me, I'm No. 61 in the world and I have no pressure,'' Lu said.I just go on the court and play my game and it's not about who is better. But I think I served more consistent than him today. And in the fourth set and final set, I played more aggressive than him.''

Lu, who took up tennis because of his father's love of the sport, was only able to compete internationally because of a generous sponsor in Taiwan, where tennis lags way behind the popularity of baseball, badminton and table tennis.

He practices in Germany and is coached by Rainer Schuettler's coach, Dirk Hordoff, who was court-side for part of his match Wednesday. But Lu is quick to point out that he's not shunning his native country's help.

We are the first ones to be top 100, so they (Taiwan tennis officials) have really no experience, like how we should do in professional tennis,'' Lu said.So we look for a coach with more experience. I'm not saying Taiwan coaching is bad, but they need some time to get experience.''

Lu, nicknamed ``Randy'' by his former English teacher because it was easier to pronounce than his hyphenated first name, followed Stefan Edberg, Pete Sampras, Andre Agassi, Jim Courier and Chinese-American player Michael Chang when he was growing up.

Beating one of the newest big names in tennis, Murray, in straight sets in Beijing was one of his career highlights. His win over Nalbandian on Wednesday was right up there.

I think it has different meanings for me, because Olympics is to play for my country,'' Lu said.But here, it is a Grand Slam. I think for me it's the biggest of tennis events. And it's one big step to get to the third round.''

On Friday, he'll face 21st-seed Tommy Robredo of Spain. Robredo and Lu have played each other just once, with the Spanish player winning in straight sets at Tokyo in 2006.