Reigning champion Nick Matthew survived a first round scare in the first round of the Davenport North American Open before beating Colombian outsider Miguel Angel Rodriguez to progress in the second PSA World Series squash event of the year at the Westwood Club in Richmond, Virginia.
World champion Matthew squeezed home 14-12, 10-12, 11-9, 9-11, 11-5 in a 92-minute marathon.
The Englishman, who is bidding for a third consecutive NAO title, said: "Miguel is capable of giving all the top guys a scare and I was almost ready to get on the plane home at the end of the fourth game. Fortunately I got a good start in the fifth and I'm glad to get through. Mentally, that's one hurdle over and I've got to get it out of my system and get ready for the next match."
The 31-year-old world number one from Sheffield faces Finland's Olli Tuominen, who withstood a fierce fightback from America's seven-time national champion Julian Illingworth.
Tuominen held match ball at 10-5 in the fourth game but Illingworth produced a spectacular spell of attacking squash to draw level. Then it was his turn to waste two game balls before Tuominen clinched victory by a 15-13 margin.
Ramy Ashour, runner-up to Matthew for the past two years, returned to action after an injury break and overwhelmed Australian Matthew Karwalski in just 23 minutes.
The Egyptian said: "I don't want to talk about my injuries any more. That's all I have talked about for the past few months and all I want to do is concentrate on playing squash. I am so happy to be back, and especially here in Richmond."
His opponent, Karwalski, admitted: "That was just like going to squash school and being given a lesson. It didn't matter what I did, Ramy had an answer for it. Even if I hit a good ball past him and sent him to the back of the court, he would just run past me and hit a winner.
"In fact, he hit winners from anywhere and everywhere," added the 26-year-old from New South Wales. "He hit some shots I have never even seen before. At times I just had no idea what to do. There is no doubt that, when he is free from injury, Ramy is the best player in the world."
Ashour, the No4 seed this week, posed for pictures in a Jaguar parked next to the court in the Westwood Club, and joked: "I am not worried about the prize money. I'll just take the Jaguar."
Ashour now meets another Australian Cameron Pilley, who won a colourful clash with Canadian Shawn Delierre. The match ended in controversial fashion as the qualifier from Montreal was punished with two conduct strokes for audible obscenities, the second coming on match ball.
The biggest casualty of the day came when Alister Walker of Botswana removed number seven seed Laurens Jan Anjema of The Netherlands. New York-based Walker squandered five match balls from 10-5 up in the fifth game before finally clinching it 12-10.
Australian Zac Alexander became the second qualifier to claim a place in the last 16 round when he upset Scotland's Alan Clyne 11-6, 11-3, 11-8. The New York-based Queenslander will now fifth seed Karim Darwish, the experienced Egyptian who needed almost an hour to quash French qualifier Mathieu Castagnet 12-10, 11-6, 7-11, 11-5.
RESULTS: PSA World Series Davenport North American Open, Richmond, Virginia, USA
1st round (lower half of draw):
 Ramy Ashour (EGY) bt [Q] Matthew Karwalski (AUS) 11-8, 11-1, 11-8 (23m)
Cameron Pilley (AUS) bt [Q] Shawn Delierre (CAN) 11-6, 11-8, 9-11, 11-8 (60m)
[Q] Zac Alexander (AUS) bt Alan Clyne (SCO) 11-6, 11-3, 11-8 (40m)
 Karim Darwish (EGY) bt [Q] Mathieu Castagnet (FRA) 12-10, 11-6, 7-11, 11-5 (59m)
Alister Walker (BOT) bt  Laurens Jan Anjema (NED) 7-11, 11-8, 8-11, 11-5, 12-10 (70m)
Simon Rosner (GER) bt Chris Ryder (ENG) 5-11, 11-5, 11-5, 11-9 (57m)
Olli Tuominen (FIN) bt Julian Illingworth (USA) 8-11, 11-7, 11-2, 15-13 (55m)
 Nick Matthew (ENG) bt Miguel Angel Rodriguez (COL) 14-12, 10-12, 11-9, 9-11, 11-5 (92m)
2nd round line-up:
 James Willstrop (ENG) v Thierry Lincou (FRA)
 Amr Shabana (EGY) v Adrian Grant (ENG)
 Mohd Azlan Iskandar (MAS) v [Q] Karim Abdel Gawad (EGY)
 Gregory Gaultier (FRA) v Shahier Razik (CAN)
 Ramy Ashour (EGY) v Cameron Pilley (AUS)
 Karim Darwish (EGY) v [Q] Zac Alexander (AUS)
Alister Walker (BOT) v Simon Rosner (GER)
 Nick Matthew (ENG) v Olli Tuominen (FIN)