The pair were up against each other again at the Lane nine days ago as Giggs helped United secure a 2-0 win towards another Premiership title - now secured by Arsenal's defeat to Leeds.
Simon had a handful of Spurs appearances to his name two years ago and had just made his full Welsh debut against Ukraine.
The midfielder is now seen as a mainstay of Glenn Hoddle's side - starting 35 of 40 games so far this term - and of the Welsh revival under Mark Hughes.
Simon has played in all of Wales qualifying fixtures as they charge towards Euro 2004 and what will be their first major finals since 1958.
The highlight his 2002-03 season would no doubt be his goal in Wales' memorable win against Italy at a euphoric Millennium Stadium in October.
That goal no doubt went a long way in pursuading judges to add the Welsh Player of the Year title to the same Spurs title he now holds.
For wing wizard Giggs, Simon's emergence alongside the likes of Craig Bellamy, Jason Koumas, Daniel Gabbidon, Robert Earnshaw and even Robbie Savage means he can finally target a major championship with confidence.
"Simon's gone from strength to strength and made himself a regular not just at Tottenham but for his national side as well," said Giggs after Sunday's encounter.
"He has made that step from club football to international football very easily and that's not an easy thing to do. It's pleasing to see for myself, Simon, Spurs and Wales.
"The arrival of Simon and Craig Bellamy in the last couple of years has been a big factor for Wales.
"We can now compete. We've got the players, the team and squad to do that now. We've put ourselves in a strong position and we just need to see it through now."
In May 2001, Ryan Giggs talked in glowing terms about a young Welsh star just starting to break through at Spurs - two years on and Simon Davies is fulfilling the promise his hero saw in him.