Reigning MLS Cup champions Los Angeles Galaxy moved closer to returning to Major League Soccer's title match on Sunday with a 3-0 victory over Seattle Sounders in the first leg of the Western Conference finals.
Keane opened the scoring in first-half injury time, when Landon Donovan chipped an inch-perfect ball to the back post.
The Irishman was unmarked and calmly headed past Sounders goalkeeper Michael Gspurning.
Keane scored again in the 67th minute, three minutes after Magee had made it 2-0 with a goal that capped a counter attack launched by Keane.
The victory sends the Galaxy into the return leg next Sunday in Seattle with a comfortable cushion as they seek to advance to the MLS Cup final on 1 December.
They could well find themselves in a rematch with the team they vanquished in the MLS Cup last year, Houston Dynamo, who defeated DC United 3-1 in Sunday's Eastern Conference finals first leg match.
Andre Hainault, Will Bruin and Kofi Sarkodie scored second-half goals to put Houston in control of the tie that will conclude next Sunday at RFK Stadium in Washington.
Nick DeLeon scored for United, who haven't lost at home since their season-opener against Sporting Kansas City in March.
DeLeon slotted home a rebound in the 27th minute for his second goal of the playoffs.
But Hainault pulled Houston level in the 51st, Bruin added a second goal for Houston in the 68th and Sarkodie beat goalkeeper Joe Willis in the 81st.