I did not state the year and perhaps I should have. In 1987, at Wimbledon, MN was very much the favorite and still the dominant presence. Steffi was the underdog at that stage. Not sure what you are aiming at in regards to '91, but the crowd was behind Martina as the sentimental favorite. Yes, it is both obvious and REAL. I think you are just trolling. Have fun.You think Steffi was the "underdog" in 89 when she beat Navratilova in three high-profile finals? The "young lady" had won the Golden Slam the year before...
"It was most obvious in their '91 USO semifinal", that is even better!
Which other matches come to your mind when the crowds rooted more for Navratilova than for Graf, maybe a bit less obvious?
Face the reality, Navratilova and Serena never were especially popular, for different reasons.