You can edit this in Plugins >> Editor >> World Cup Predictor, opening the file world-cup-predictor/wcp-reports.class.php and search for this code in line 1079:
$sql = "SELECT m.match_id,
h.country AS home_country, a.country AS away_country,
h.team_url AS home_url, a.team_url AS away_url,
h.name AS home_team_name, home_goals, home_penalties,
a.name AS away_team_name, away_goals, away_penalties,
is_group, extra_time, is_result
FROM
{$wpdb->prefix}{$this->prefix}match m,
{$wpdb->prefix}{$this->prefix}stage s,
{$wpdb->prefix}{$this->prefix}team h,
{$wpdb->prefix}{$this->prefix}team a
WHERE
s.stage_id = m.stage_id AND (m.match_id = %d OR %d = -1) $throttle AND
h.team_id = m.home_team_id AND a.team_id = m.away_team_id AND (m.is_result OR EXISTS
(SELECT * FROM {$wpdb->prefix}{$this->prefix}prediction p WHERE p.match_id = m.match_id) )
ORDER BY
m.kickoff";
Change the ORDER BY m.kickoff para ORDER BY m.kickoff DESC.