New South Welshman Matthew Karwalski and Queensland’s Zac Alexander reached the main draw of the North American Open world series squash tournament at Richmond in Virginia after winning their final qualifying matches on Sunday.

Karwalski stunned qualifying top seed Martin Knight of New Zealand 12-10 11-7 11-5, while Alexander came from 2-1 down to beat Englishman Chris Simpson 7-11 11-6 7-11 11-8 11-6.

They join Australian No.1 Cameron Pilley and Ryan Cuskelly in the first round of the prestigious tournament.

While Alexander was favoured to beat Simpson, Karwalski surprised many with the ease of his win over the classy Knight.

But he said time spent training with recently-retired Australian great David Palmer in Orlando had helped his game enormously.

“I am very grateful to David for his advice, support and guidance,” Karwalski said.

“He has given me tremendous help to prepare for this tournament, working on fitness, tactics and mental preparation.

“In the past, I may have lost concentration when something has gone against me and lost a string of points in quick succession, but David has helped me to become mentally stronger.”