DOHA  - World champion Nick Matthew admitted he was in trouble against Australia's Zac Alexander who might have been using "reverse psychology", before carrying his bid to achieve a title hat-trick into the last 16 on Monday.

The 32-year-old Englishman was made to fight for survival before coming through 8-11, 11-5, 11-5, 11-5 against Alexander who packed his bags for the airport and brought them in the car they shared en route to the arena. "For the first game and a half I wasn't anywhere," said Matthew, who was 3-5 down in the second set having lost the first in the world championship second round tie.

"I don't know if packing his bags was reverse psychology, but he played really well and I had to get my act together. I was in trouble there and it was ugly for a while. I had to throw tactics out of the window and just fight and get some adrenaline going. It wasn't easy and I had to tell myself to try to enjoy it because I felt maybe a little bit tense. He had packed his bags and it was like I wasn't going to be there tomorrow."

Alexander, who is coached by former world champion Rodney Martin, a compatriot based in New York, struck some uninhibited winners, and might have become inspired to make more of them had he come close to going two games ahead. Instead as Matthew began to work at keeping the ball tighter and feeding him fewer volleys with cross court drives, Alexander began to make mistakes.

When that happened the champion showed his vast experience, turning the screw with disciplined and accurate driving and tight counter-drops, and keeping his margin of error high. "You have to get it right on this (cold) court or you can be in trouble," Matthew said. "But it's made me more alert, which may help me in the next round."

That however is against Tarek Momen, the rising 13th-seeded Egyptian, who beat Matthew when they last played on this court, a year ago in the Qatar Classic.

Three other big names also reached the last 16 in the same half - two former world champions from Egypt, Amr Shabana and Ramy Ashour, and Greg Gaultier, the former world number one from France.

Matthew could face Shabana if they both win once more, and he may consider it further reverse psychology that the 33-year-old disarmingly claimed he was "just happy with four world titles" after beating Joe Lee, a promising Englishman, for only ten points.

Gaultier also looked good during a 11-9, 11-7, 11-9 win over Miguel Angel Rodriguez, the fast-moving Colombian, but the most impressive of them all was Ashour, who moved brilliantly during an 11-6, 11-2, 11-9 success against Adrian Grant, a top 20 Englishman.

Afterwards Ashour claimed that his new fitness, generated with the help of sports science experts at Aspire in Qatar, was not only "one of the biggest changes of my career" but "has changed my life."