Since finishing runner-up in the capital last year Murray has struggled for consistency this season, but she appeared back to her best on the biggest stage as qualifying got underway.
The 23-year-old recorded second-place finishes in both the swimming and the fencing disciplines, putting her top of Group B heading into the combined.
Murray is sitting pretty on 2136 points which gives her a 15-second advantage over Russia’s Donata Rimsaite, while Sarolta Kovacs will go third in the combined.
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Defending champion and fellow Brit Mhairi Spence currently sits 11th and will start the combined some 44 seconds behind Murray.
Spence has a total of 1960 points and faces an uphill battle if she is to get her hands back on the title.
Elsewhere for Great Britain, Freyja Prentice is seventh in qualifying Group A while Kate French is 12th.
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