Port Adelaide’s giantkilling run in September was showing no signs of ending at halftime of Friday’s AFL semi-final at the MCG after the visitors claimed a 23-point advantage.

First-year coach Ken Hinkley’s Port side lead the Cats 7.5 (47) to 3.6 (24) at the main break, with the winner to progress to next Friday night’s preliminary final against Hawthorn.

Port’s Kane Cornes has dominated midfield while James Kelly has been busy for the Cats.

Geelong have been held to their lowest first-half score of the season and appear in danger of going out in straight sets after qualifying for the finals in second spot.

Veteran forward Paul Chapman marked and played on to snap a couple of first-term goals for the Cats, using his triple-premiership experience against 18-year-old Power defender Sam Colquhoun.

Port forced errors in Geelong’s defence and the visitors levelled the scores at the 24-minute mark after goals to Brad Ebert and Angus Monfries.

A third goal to Port, which came from a throwing-the-ball decision against Geelong’s Josh Hunt who was tackled at half-back, put the Power six points ahead at quarter-time 3.2 (20) to 2.2 (14) after ruckman Matthew Lobbe slotted the goal from 35 metres out.

Geelong continued to struggle with their ball use and Port booted a fourth goal through Justin Westhoff early in the second quarter before Geelong replied through Mitch Duncan.

Monfries was in everything for Port and chipped a pass to Tom Logan as the Power grabbed a 15-point advantage.

The Cats wasted several goal-scoring opportunities before Port Adelaide went forward again where Westhoff won a free kick for a high tackle and kicked his second goal from a tight angle at the 26-minute mark.

Monfries was involved again three minutes later as he thumped the ball forward and Robbie Gray kicked a goal from a free kick against Josh Hunt as Port surged 23 points clear.

Key forwards Hawkins and James Podsiadly have been goalless for the Cats who have won their past nine games against Port.