Defeating Tabur stretched Sinner's winning streak to 30 matches, which has already yielded clay-court titles in Monte Carlo, Madrid and Rome.
His most recent triumph in Rome meant he completed the full set of nine ATP Masters 1000 titles - known as the 'career Golden Masters'.
Sinner dominated the opening two sets, with winners flowing from his racquet while unforced errors were kept to a minimum.
Tabur did not have a break point in the match as Sinner wrapped up victory in two hours and eight minutes.
Sinner's path to the Coupe des Mousquetaires is already without one major obstacle because Alcaraz is absent - and seeds tumbled in his half of the draw on Tuesday.
Sixth seed Daniil Medvedev and ninth seed Alexander Bublik were defeated in the first round, while fourth seed Felix Auger-Aliassime needed a fifth-set tie-break to beat world number 57 Daniel Altmaier.
Auger-Aliassime is the next highest-ranked player in Sinner's half of the draw, but the Canadian has lost his past five matches against the four-time major winner.
Up next for world number one Sinner is Argentina's 56th-ranked Juan Manuel Cerundolo, who knocked out Great Britain's Jacob Fearnley on Tuesday.
