Brian McCaul scored a hat-trick to help Glenavon off the bottom of the table with a win over Carrick Rangers.
Thomas Hyland gave Carrick the lead with a header from six yards in the third minute but McCaul shot home the equaliser on 14 minutes.
O'Neill headed in Marcus Kane's cross from the right a minute later, before Marcus Kane was sent-off.
McCaul fired in a low left-foot volley from 12 yards after 70 and completed his hat-trick on 84.
Hyland's early goal rocked the home side but McCaul finished well after meeting Grant's through ball to level.
After O'Neill had nudged Carrick in front, Glenavon's Kyle Cherry and Carrick's Paul Heatley both hit the woodwork.
Kyle Neill saw his low shot go wide of the post after half-time but McCaul made the most of his chance when the ball fell to him with 20 minutes remaining.
Kane's dismissal on 69 minutes was for a second bookable offence.