The big Argentinean had come from a set down to defeat Leonardo Mayer and Philipp Kohlschreiber in the previous two rounds, but there were no such struggles on Sunday (AEDT) as he cruised past Raonic 6-2 6-3.

Del Potro has only won a quarter of his 24 meetings against Federer, who is now enjoying his best start to a season after moving to 17-0 by fighting back from behind to outlast Borna Coric in the first semi-final.

But on this evidence, Del Potro can retain some hope of lifting a maiden Masters 1000 title after producing some scintillating tennis in the California sunshine.

The world No.8 was quickly into his stride, winding up that famous forehand to good effect as early as the third game by thumping one down the line to secure a break to love.

Raonic chose to serve and volley on break point two games later, a tactic that did not pay off as he found the net and handed Del Potro a 4-1 lead. A stunning inside-out forehand gave the No.6 seed a hold to love and the opening set.

As in the first, Del Potro broke in game three of the second, thanks in part to two crunching shots. A cross-court forehand winner was followed by a backhand down the line to set up two break points and, feeling the pressure, Raonic double-faulted.

The Canadian did secure comfortable holds in each of his next two service games but Del Potro, the runner-up to Rafael Nadal at this tournament in 2013, was not to be denied, breaking again in game nine after Raonic's netted backhand to advance to his fourth Masters final.