Eto'o shines in Barcelona's victory
It's good to know that the Brazilian had returned to Frank Rijkaard's side - along with compatriot Sylvinho - after a foot injury, and his precise cut-back from the by-line gifted Eto'o with an impossible chance to miss.
In fact, the weak Osasuna were an accident waiting to happen and in the 27th minute, the African striker doubled his, and Barca's, tally after latching on to Enrique Corrales' misdirected headed clearance.
Spotting goalkeeper Ricardo off his line, Eto'o chipped the ball home first time with the outside of the right boot. This mouth-watering combination of poaching skills and confident finishing from arguably the world's most powerful striker at the moment sent the home crowd into overdrive.
Nine minutes later, Eto'o turned from scorer to provider after dogged persistence saw the Liga golden boot charge down a hapless clearance from Ricardo. Indeed, the explosive striker squared the ball back to Argentinian sensation Messi, who enticed Ricardo forward before duly nutmeging the former Manchester United bench-warmer to notch the champions' third.
And following the first-half fireworks, the second-half was a relatively tame affair, with Osasuna trying to fight their way back into the game and score a goal that would have done a little to save their honour.
Substitute Valmiro Valdo went the closest, but his woeful shot into the side netting once Lilian Thuram was caught out playing the offside trap showed just why he started the game on the bench.
Argentine young star Messi almost scored his second goal of the night after 61 minutes when his low right-foot effort was diverted onto the far post by Ricardo in what was Barcelona's best effort.
Later, in the 70th minute, one player notoriously omitted from his country's world cup squad - Ludovic Giuly - replaced another footballer notoriously ramshackle during his nation's underperformance in Germany - Ronaldinho.
The Brazilian star had shown glimpses of his best form during the first half - particularly in the build up to the opening goal - but was quick to lose his influence after the break.
Then, Ronaldinho watched the remainder of the match after his substitution with an ice-pack on his left knee, prompting concerns about his availability for Barca's opening Champions League match on Tuesday.