Williams had taken the first set, and a two game to love lead in the second but then proceeded to lose seven games on the run to concede the second set. She had seven break points on her opponent's serve early in the third set but failed to take them until the seventh game when she established what seemed to be a vital 4-3 lead.
But Williams immediately dropped her own serve to allow Gryzbowska to level at 4-4. The Pole won her own serve and then broke Williams to love to take the match and a place in the second round.
Williams had stomped her way back from Court One to a locker-room but by the time she came up for the press conference she was trying to put on a brave face at the end of what has been a difficult week.
"I am not disappointed. It's my first Wimbledon and there will be many more to come. I tried to do my best and I never gave up during the match. As long as I know that I didn't, I think I'll do better as the year goes on. I'm not disappointed at all.''
Her eyes said otherwise however. She was blatantly betrayed by her own lack of playing experience, not just on grass, exposing the flaws in this roughly hewn diamond. For all the power and reach in her game - she smacked one serve down at 114mph - she was, at best, tactically naive.
In the third game of the final set, having led 0-40 on Gryzbowska's serve she lost one break point by simply knocking an easy ball to the Pole's backhand, blatantly her strongest side and promptly suffered the consequences.
"She had a good backhand,'' Williams said in appreciation, albeit too late for her own progress. "She hit it very flat, took a lot balls early and so it was very solid.''
The two young girls had come on to Court One at 12.15 as the awful weather finally relented, but the conditions were still far from perfect, with a heavy atmosphere and a treacherous slippyness in the lush turf. Wearing big, basketball-style tennis shoes Williams slithered to a double fault on her first ever service at Wimbledon, an apt omen as she was to serve 11 more to undermine her chances.
But with her green, purple and white hair beads swishing through the air Williams soon began to unleash her trademark forehands, although with more power then placement. She also stuck consistently to the baseline for most of the first set, aiming to out gun Gryzbowska with her ground strokes.
In the seventh game a booming forehand set up a first service break which Williams exploited to take the set, although a double fault on set point was some indication of her nervousness. With an immediate break and a win on her serve in the second set, a planetary alignment looked good for Venus.
But she then lost her serve three times as Gryzbowska produced her run of seven winning games. And though games went with serve early in the final set, Williams' vulnerability brought two more crucial losses. In the final game it wouldn't be untrue to say that Gryzbowska toyed with her, moving her around the court at will before ripping off big winners.
Williams mainly has a steep learning curve ahead of her and the role of her father Richard as coach may well come under further scrutiny - he hadn't even travelled to Wimbledon, and the subject brought a touch of tetchiness to the post-game interview. But the immediate demands on Williams' future are for her high school grades in a few weeks' time. Back to school seemed to have double meaning after yesterday.