The men's main draw kicked off with a huge upset as Nicolas Mueller sensationally beat fifth seed Amr Shabana - who won the US Open just a few days ago - in straight games.
The young Swiss played superbly well against an out of sorts Egyptian - who made the final in his last three appearances here - to reverse the result of their only previous meeting, ironically enough in the first round here last year.
"Today is probably the best match I played in my life, even if I realise that Shabana was not 100%," said Mueller.
Tarek Momen got the better of fellow-Egyptian Omar Abdel Aziz in three close games, qualifier Aziz getting frustrated with not being able to get a firm footing on the newly-resurfaced floor of the glass court.
"I think we really played well today, both of us," said Momen. "I’m happy with the way I played, even if I made a few too many errors."
The much-anticipated all-Finnish clash between Olli Tuominen and Henrik Mustonen fizzled out after just two minutes when Tuominen retired with a calf injury sustained earlier in the week proved too much for him to play with, allowing Mustonen a quick passage into round two.
Mustonen will meet a similarly fresh defending champion after Karim Darwish demolished Malaysian qualifier Kamran Khan 11/2, 11/2, 11/2 in 20 minutes.
The evening session started with two identical scorelines as top seed Nick Matthew and Malaysia's Azlan Iskandar both won tough first games before going on to record 11/9, 11/4, 11/4 victories.
Matthew found Pakistan's Aamir Atlas Khan a handful in the first game, with Askandar having the same problem with Qatari wildcard Abdulla Al Tamimi - two small, quick players - but both found the going easier thereafter.
Siddarth Suchde delivered a second upset of the day as the Indian qualifier put out Egypt's Ali Anwar Reda. After taking a two-game lead Suchde looked set for a straight games win, but although Reda fought back to take the third, Suchde was unstoppable in the fourth.
"It’s quite tough to come from the qualification, you have no easy matches nowadays," said a delighted Suchde, "and then, you’ve got to adapt from the traditional court to the glass court. But the good thing is you’ve got no pressure on you at all."
Suchde's next opponent will be France's sixth seed Gregory Gaultier, who was in no mood to allow another upset, dismissing young Egyptian qualifier Mohamed Abouelgar in just 30 minutes to conclude the day's play.
Merhan seals Egyptian hat-trick as Bailey marks welcome return ...
You won't be surprised to hear that Egypt collected three of the main draw spots on offer, but England grabbed two with players from opposite ends of the experience spectrum ...
Qualifying top seed Emily Whitlock became the first to qualify for the women's main draw with a solid enough 3/1 win over Egypt's Salma Hany.
"I was really nervous," admitted Whitlock, who qualifies for her second major event in a row after the Australian Open. "It took ages to get here and even though I had a bye I was feeling the pressure of being expected to qualify. I only felt really comfortable in the third game, but I'm just glad to qualify, and especially to get it out of the way early in the day instead of having to hang around waiting!"
Farah Abdel Meguid notched up the first Egyptian win of the day, recovering from a slow start - 7-0 down in the first game - to beat Siyoli Waters in four games.
"I was nervous at the start," admitted the tall Egyptian teenager, "I just had to try to cool it down as she's very fast." She did that very effectively, narrowly failing to pull back that first game deficit but taking the next three with increasing ease.
"I'm pleased to qualify for my second big tournament, after the worlds last year, I just hope I don't get to play another Egyptian," she added.
After virtually a full year out, England's Tania Bailey made a welcome return to WISPA action, beating young Dutchwoman Milou Van Der Heijden in four games.
"I wasn't exactly nervous but I didn't feel comfortable," admitted the former world number four after the match, "more just apprehensive about what would happen as I haven't played a tournament, and haven't played another woman for such a long time!
"It almost felt as if I was starting over again as an 18 year old, I'd forgotten about how to prepare, when I should eat, all the basic stuff like that.
"Milou played well, she hits the ball nicely and takes it in short like I'm not used to playing the men at home. In the middle of the match I wasn't feeling confident at all, I really thought I was going to lose. But then the experience seemed to kick in, I took a few points in a row in the fourth and I managed to pull through.
The afternoon session was rounded off with a comfortable enough win for South Africa's Tenille Van Der Merwe over Kiwi Kylie Lindsay. "That's a good start to the tournament for me," said Tenille, "now let's just see who I get next!"
"It's good to be back - I said after my knee operation in February that if it allowed me to play one more match then that would do me. I've had that match so let's just see what happens, although having started I definitely want more. I still feel I can compete with any of the girls on the day, so let's see ..."
The second session started with a win for Siti Munirah Jusoh which made it four Malaysians in the main draw, but Olga Ertlova made her work all the way, failing to capitalise on two game balls in the first and hold the score close until late in each of the next two games.
"I was a bit nervous and slow to get started," said the Malaysian, but I felt more comfortable as the match wore on and I'm really pleased to qualify for my first really big tournament, especially as it's my first time here."
Another who will be making her first appearance in a world series main draw is Germany's Sina Wall, who shrugged off losing the first game to Lauren Selby by taking an 8/0 lead in the second on the way to securing a 3/1 victory.
"I had to change my game after the first," said Wall, "I was playing too many crosscourts and she was able to put it away on the volley. I kept it straighter for the next three games and was able to control the play more.
"I'm delighted to make the main draw, it should be good for my ranking too!"
Egyptian teenager Yathreb Adel, who has been making waves in WISPA events in the US of late, enjoyed a similar win as she came from a game down to beat Japan's Misaki Kobayashi in four.
"I was playing the wrong way in the first," admitted Adel. "She was hitting it so hard, I had to try to slow it down and play more lengths. Then I was able to find my own and became more confident.
Possibly the toughest match, and definitely the happiest winner, was saved until last. After winning a nailbiting five-setter yesterday, Merhan Amr Mahmoud turned in a determined performance in beating qualifying second seed Orla Noom in four games. She nearly let a good lead slip in the fourth game, but finally got the win at the end of some long tough rallies, and how delighted she - and the Egyptian squad which had been occupying the front two rows behind court 3 all day - were:
"I'm so happy, I finally achieved something I can tell my children about! I played here last year and in the worlds in Sharm, but I did nothing, but now after two hard matches I finally made it to the main draw.
"I want to thank my Dad, I wish he could be here!"
Men's Round One (top half):
Nicolas Mueller (Sui) bt  Amr Shabana (Egy) 11/6, 11/7, 11/4 (30m)
Tarek Momen (Egy) bt [Q] Omar Abdel Aziz (Egy) 15/13, 11/8, 11/5 (47m)
[Q] Henrik Mustonen (Fin) bt Olli Tuominen (Fin) 4/0 rtd (2m)
 Karim Darwish (Egy) bt [Q] Kamran Khan (Mas) 11/2, 11/2, 11/2 (20m)
 Nick Matthew (Eng) bt Aamir Atlas Khan (Pak) 11/9, 11/4, 11/4 (38m)
Azlan Iskandar (Mas) bt Abdulla Al Tamimi (Qat) 11/9, 11/4, 11/4 (24m)
[Q] Siddarth Suchde (Ind) bt Ali Anwar Reda (Egy) 11/8, 11/6, 9/11, 11/1 (64m)
 Gregory Gaultier (Fra) bt [Q] Mohamed Abouelgar (Egy) 11/8, 11/3, 11/4 (30m)
Women's Qualifying Finals:
Emily Whitlock (Eng) bt Salma Hany (Egy) 11/7, 7/11, 11/4, 11/5 (43m) plays Low
Farah Abdel Meguid (Egy) bt Siyoli Waters (Rsa) 8/11, 11/5, 11/6, 11/2 (33m) plays Hawkes
Tania Bailey (Eng) bt Milou Van Der Heijden 11/6, 11/3, 9/11, 11/8 (36m) plays El Weleily
Tenille Van Der Merwe (Rsa) bt Kylie Lindsay (Nzl) 11/5, 11/5, 11/6 (24m) plays Serme
Siti Munirah Juson (Mas) bt Olga Ertlova (Cze) 12/10, 11/7, 11/6 (38m) plays Perry
Sina Wall (Ger) bt Lauren Selby (Eng) 10/12, 11/5, 11/4, 11/5 (37m) plays Duncalf
Yathreb Adel (Egy) bt Misaki Kobayashi (Jpn) 6/11, 11/7, 11/4, 11/5 (42m) plays Grinham
Merhan Amr Mahmoud (Egy) bt Orla Noom (Ned) 11/8, 6/11, 11/7, 11/9 (41m) plays Massaro