Maybe:
<tbody>
[TD="align: center"]1[/TD]
[TD="align: right"]45[/TD]
[TD="align: right"]50[/TD]
[TD="align: center"]2[/TD]
[TD="align: right"]62[/TD]
[TD="align: right"]11[/TD]
[TD="align: center"]3[/TD]
[TD="align: right"]50[/TD]
[TD="align: right"][/TD]
[TD="align: center"]4[/TD]
[TD="align: right"]82[/TD]
[TD="align: right"][/TD]
[TD="align: center"]5[/TD]
[TD="align: right"]11[/TD]
[TD="align: right"][/TD]
</tbody>
Sheet2
[TABLE="width: 85%"]
<tbody>[TR]
[TD]
Worksheet Formulas[TABLE="width: 100%"]
<tbody>[TR="bgcolor: #DAE7F5"]
[TH]Cell[/TH]
[TH="align: left"]Formula[/TH]
[/TR]
[TR]
[TH="bgcolor: #DAE7F5"]B2[/TH]
[TD="align: left"]=LOOKUP(
2,1/(A2:A5< A1:A4),A2:A5)[/TD]
[/TR]
</tbody>[/TABLE]
[/TD]
[/TR]
</tbody>[/TABLE]
[TABLE="width: 85%"]
<tbody>[TR]
[TD]
Array Formulas[TABLE="width: 100%"]
<tbody>[TR="bgcolor: #DAE7F5"]
[TH]Cell[/TH]
[TH="align: left"]Formula[/TH]
[/TR]
[TR]
[TH="bgcolor: #DAE7F5"]B1[/TH]
[TD="align: left"]{=INDEX(
A2:A5,MIN(IF(A2:A5-A1:A4<0,ROW(A2:A5)-ROW(A2)+1)))}[/TD]
[/TR]
</tbody>[/TABLE]
Entered with Ctrl+Shift+Enter. If entered correctly, Excel will surround with curly braces {}.
Note: Do not try and enter the {} manually yourself[/TD]
[/TR]
</tbody>[/TABLE]
The B1 formula will find the first time a number is less than the row above, the B2 formula finds the last time a number is less than the row above. If you're sure it can only happen once, I'd use the B2 formula since it's shorter.