Well, technically Windows 2.1 (released May 1988) came before OS/2 1.1 (released October 1988). OS/2 1.0 was text-only. So at least for 5 months in 1998, Windows technically beat OS/2.
And OS/2 1.1 was very similar to Windows 2.1, so it's arguable if it was actually much better.
OS/2 1.2 was a massive leap though, not only beating Microsoft GUI wise by a whole year, they even implemented tons of advanced features that we didn't see until Windows 95.