There was a thread on tennis.com about "if Federer were to lose to Gonzalez or Haas, it would be the biggest upset in a grand slam final since..." The popular pick was (to my mind) an odd one--Sampras over Safin in 2000. I think people are forgetting that Sampras had slid to #4 by that point and had had a lousy summer, including a loss to Safin in Toronto. I can think of several grand slam finals that surprised me more: Coria over Gaudio at the 2004 French, Costa over Ferrero at the 2002 French, Johansson over Safin at 2002 Australian. I think I would say that if Federer were somehow to lose, it would be the biggest upset since Kuerten (who was a nobody ranked #66 in the world at the time) beat Bruguera at the 1997 French.

iva majoli over hingis in the 97 french. hingis was totally dominating women's tennis, and would've ended up winning the grand slam.

Arantxa Sanchez over Steffi Graf at Roland Garros in 1989. Steffi had won the last 5 slams and was ASV was a relative unknown.

Are upsets contagious? Interesting that the '97 French had big upsets in both the men's and women's and so did '89. Chang over Edberg was certainly unexpected, though Chang wasn't on his best surface. I wasn't thinking of the women's side.

I agree that Hingis and Graf are better comparisons because it's not the weakness of the challenger (Gonzalez is smoking!), but the overwhelming strength of the favorite in this case.

Arthur Ashe beating Jimmy Connors in the 1975 Wimbledon final was a pretty big shocker as well. Not that much of a difference in their rankings but Jimmy was at his most dominant and Ashe just steamrolled him.

And I don't think too many people gave Conchita Martinex much of a shot against Martina Navratilova when they met in the Wimbledon final.

Wilander over Vilas in the '81 French title was a stunner.

I confused by the way you're writing the upsets ... Sampras over Safin; Coria over Gaudio; etc. Isn't that backwards? Not that it matters, really, since I know who won those matches ... but, for instance, I would say it was Safin over Sampras at the 2000 US Open to take the title. No? But I digress.

Petr Korda over Marcelo Rios in Australia ('98) was an odd one. Rios was the man who should have ended his career with at least one Slam, but Korda kicked his ass. Of course, we later found out that Korda was on the juice.

How about 30-year-old Andres Gomez beating 19-year-old Andre Agassi at the 1990 French Open?

Speaking of 1990, no one thought Gaby was gonna beat Steffi in the '90 US Open final. Mary Carillo said "this match has 6-2, 6-2 written all over it because of how well Graf is playing." HA! Not the biggest upset in history by any stretch, but I'm just saying.

And remember when Pam Shriver FINALLY used her grass court prowess to beat Chrissie and Martina at ... oh, wait. Nevermind.

Yeah, I spaced when I was writing the upsets. Coria over Gaudio just seems like the more logical order!

And Sabatini over Graf is not a bad comparison as Steffi had a dominating head-to-head with Gaby and was on a big winning streak at the time. I don't really remember the '90 French, but looking over it, I don't think Gomez beating Agassi should really have been a big surprise. There wasn't a big difference in rankings going in (5 vs 7) and Andre was a bit of a flake at the time.

I don't see how Gaby beating Steffi was a big upset. Gaby was always considered a formidable opponent for Graf.

I'm going with Guga over Bruguera at the 1997 French Open. JC is right: Guga was a nobody at the time, and given the state of the men's game in the late 90's, I'm sure there were many who wrote him off as a one-Slam wonder.

For the women, there are two that come to recent mind: Sharapova over Serena Williams at Wimbledon '04, and Serena herself beating Hingis at the U.S. Open '99. Both were 17 at the time and playing established champions, so I doubt too many expected them both to win in straight sets.

Capriati beating Hingis in the Aussie Open Final of 2001 (Jen was 0-5 vs. Hingis)

Martinez beating Navritalova in the Wimbledon Final of 1994 (Conchita on grass?)

Johansson beating Safin in the Aussie Open Final of 2002 (2 cute asses but Marat flamed out there).

Bruguera beating Courier in the French Open Final of 1993 (Yeah, Sergi was a claycourter but Jim had won it the previous 2 years)!

Mandlikova beating Navritalova in the U.S. Open Final of 1985 (Hana was in the second tier behind Chrissie and Martina but shone through here)!

Johannson over Safin

Costa over Federer

Gaudio over Coria

Kuerten over Bruguera

Majoli over Hingis

and one not mentioned but to me was pretty shocking was Serena beating Hingis in the 99 Us Open final.