Caley are bidding to win the league for the fourth season in a row, and the title race looks like it will go down to the wire with Pentland still to play them twice.
Timbers beat Pentland away in the first game of the season, so the visitors were eager to avenge that result.
Danny Lyell’s corner-kick was put into the net by a home defender to give Pentland the lead, before the hosts equalised through an Ian Cossar header in an even opening period.
Pentland were determined to secure all three points after the interval and did so with striker Craig O’Reilly supplying both assists for Connor McHarg and Robbie Polson.
Caley maintained their three-point advantage as they came from behind to win 3-1 with lethal marksman Chris Jones bagging a hat-trick.
In Saturday’s Centenary Cup, Heriot Watt enjoyed a 2-0 local derby success at home to Balerno Athletic as they advanced to the third round.
Aidan Parkinson missed a spot-kick for the students before they opened scoring on the half hour mark. After good build-up play down the right side, Guy Morgan was released and he picked out Harry Carlin who netted at the backpost.
Watt were dominant after the interval, the only surprise being it took until the 65th minute to ram home their advantage as Gregor Adams diverted Rob Malkin’s corner-kick into the net.
Meadowbank moved above Edinburgh Star into third in the Premier Division with a comprehensive 4-0 victory as Paul Martin netted all four goals to take his tally for the season to 29.
The match was stopped for 20 minutes in the opening period due to an injury to Meadowbank’s Alex Brown, with an ambulance called for a dislocated elbow.
The home side didn’t let that affect them, however, as Martin, with his back to goal, sent a looping strike into the net.
Martin then doubled their lead on the hour mark after combining with Ross Stenhouse, before heading in for his hat-trick.
With just minutes remaining, Euan Bell won a penalty kick and Martin sent the goalkeeper the wrong way.