Kyles maintained their charge with a 2-1 win at Kilmallie and Newtonmore, who have faltered slightly by their own standards this season, squeezed past newly-promoted Glasgow Mid Argyll 1-0 at Yoker.
In the preliminary round of the Camanachd Cup, Skye won the game of the day 4-2 at Beauly, Caberfeidh hammered hosts Inverness 7-2 and Kilmory beat visitors Glenorchy 5-1.
Andrew McCuish and Malcolm Clark put Oban 2-0 up by half-time. Daniel MacVicar and Aidan MacIntyre both scored early in the second half and McCuish got his own second and his team's fifth late on.
Gordon Whyte got Kyles' first at Kilmallie and Mark Graham levelled before half-time. Roddy MacDonald grabbed Kyles' winner three minutes after the restart.
Fraser MacKintosh scored for Newtonmore and Mid Argyll then managed to frustrate the title-holders for the remaining 70 minutes.
A Will Cowie hat-trick helped Skye surge back from 2-0 down at Beauly. Ross Forbes netted in the first minute and Colin MacDonald got Beauly's second.
It took Skye half an hour to respond, with all four goals - including one from Danny Morrison - then coming within 11 minutes.
Alastair MacArthur also contributed a treble as Kilmory swept Glenorchy aside while Caberfeidh's seven included two each from Kevin Bartlett, Martin MacDonald and Inverness own goals.
Newly promoted Strathglass recorded their first National Division win and moved into the top half of the table with a 2-1 success at Inveraray.
A goalless draw at home to Lovat kept Kingussie top of the Marine Harvest Premiership while Oban Camanachd thrashed Glenurquhart 5-0 at Mossfield to go second.