Please read the following table in HTML format from a webpage and then answer the question in detail according to the table. Each table cell is defined by a <td> and a </td> tag. Each table row starts with a <tr> and ends with a </tr> tag. 'rowspan=m' and 'colspan=n' represents a cell spaning over 'm' rows and 'n' columns.

Webpage title:
John Higgins
Table title:
Minor-ranking finals: 6 (3 titles, 3 runners-up)
Table:
<table id='hittask' contenteditable='False'>
<tr> <th colspan=1 rowspan=1 > Outcome </th><th colspan=1 rowspan=1 > No. </th><th colspan=1 rowspan=1 > Year </th><th colspan=1 rowspan=1 > Championship </th><th colspan=1 rowspan=1 > Opponent in the final </th><th colspan=1 rowspan=1 > Score </th></tr>
<tr> <td colspan=1 rowspan=1 > Winner </td><td colspan=1 rowspan=1 > 1. </td><td colspan=1 rowspan=1 > 2010 </td><td colspan=1 rowspan=1 > Ruhr Championship </td><td colspan=1 rowspan=1 > England Shaun Murphy </td><td colspan=1 rowspan=1 > 4–2 </td></tr>
<tr> <td colspan=1 rowspan=1 > Runner-up </td><td colspan=1 rowspan=1 > 1. </td><td colspan=1 rowspan=1 > 2010 </td><td colspan=1 rowspan=1 > Prague Classic </td><td colspan=1 rowspan=1 > England Michael Holt </td><td colspan=1 rowspan=1 > 3–4 </td></tr>
<tr> <td colspan=1 rowspan=1 > Runner-up </td><td colspan=1 rowspan=1 > 2. </td><td colspan=1 rowspan=1 > 2011 </td><td colspan=1 rowspan=1 > Players Tour Championship – Event 5 </td><td colspan=1 rowspan=1 > England Andrew Higginson </td><td colspan=1 rowspan=1 > 1–4 </td></tr>
<tr> <td colspan=1 rowspan=1 > Winner </td><td colspan=1 rowspan=1 > 2. </td><td colspan=1 rowspan=1 > 2012 </td><td colspan=1 rowspan=1 > Kay Suzanne Memorial Trophy </td><td colspan=1 rowspan=1 > England Judd Trump </td><td colspan=1 rowspan=1 > 4–2 </td></tr>
<tr> <td colspan=1 rowspan=1 > Runner-up </td><td colspan=1 rowspan=1 > 3. </td><td colspan=1 rowspan=1 > 2012 </td><td colspan=1 rowspan=1 > Bulgarian Open </td><td colspan=1 rowspan=1 > England Judd Trump </td><td colspan=1 rowspan=1 > 0–4 </td></tr>
<tr> <td class="highlighted"  colspan=1 rowspan=1 > Winner </td><td colspan=1 rowspan=1 > 3. </td><td class="highlighted"  colspan=1 rowspan=1 > 2013 </td><td class="highlighted"  colspan=1 rowspan=1 > Bulgarian Open </td><td class="highlighted"  colspan=1 rowspan=1 > Australia Neil Robertson </td><td class="highlighted"  colspan=1 rowspan=1 > 4–1 </td></tr>
</table>
Question:
How did John Higgins win the 2013 season minor-ranking Bulgarian Open?
Answer:
In the 2013 season, Higgins won the minor-ranking Bulgarian Open with a 4–1 victory over Neil Robertson in the final.