That allowed Vermeulen to restart his machine and retake his position on the grid for the third start - which fortunately went without incident and saw Casey Stoner just squeeze out Hopkins to lead into turn one, with Nicky Hayden, Shinya Nakano, Rossi, Vermeulen, Elias, Tamada, Edwards and Pedrosa following.
Thereafter, Rossi - despite some tough opposition - made his way steadily forwards; passing Roberts for fourth on lap 3 of 24, Hopkins for third on lap 6 and then Hayden for second on lap 8. The seven-times world champion then completed his ascendance by taking the lead with another turn one outbraking move, on Stoner, at the start of lap
However, another man on the move was home hero Pedrosa - who had charged from eleventh on the grid up to sixth, and was now just 2.8secs from Rossi. The Repsol Honda rider was then gifted fifth when Stoner slid out of second place on the entry to the stadium area - but Dani's day also came to an abrupt end, just over a lap later, when he lost the front of his RCV through turn one.
The diminutive triple world champion fought hard to lift his bike - and eventually remounted, with the help of marshals - but was forced to retire due to the amount of damage sustained.
The dismissal of both Stoner and Pedrosa left Rossi and Hayden to battle for victory during the second half of the event, while Roberts and Hopkins fought over a valuable podium position around 3.5secs behind, with Vermeulen and Rossi's Camel Yamaha team-mate Colin Edwards the same distance back of Hopkins as they bickered over fifth.
Rossi, Roberts and Edwards broke free to win those respective battles in the closing stages - the Italian enjoying enough of a lead to light-up the rear wheel of his M1 and wave to the fans during the last lap, before further celebrating his third victory of the season and second win in a row after a race that only 11 riders finished.
But Hayden's second place, combined with Capirossi's DNS, means that the American has now retaken sole control of the world championship standings - and lost only 5-points to Rossi, who is now up to third place but 29-points from the Repsol rider. It now remains to be seen if Capirossi and fourth in the championship Melandri can ride in next Saturday's Dutch TT...
Meanwhile, the man with most to celebrate at Barcelona was undoubtedly Roberts Jr - who took his first podium since last year's wet British Grand Prix, but more importantly claimed the first podium for his father's Team Roberts outfit since they began building their own machines back in the mid-1990s... in what was only the Honda powered KR211V's seventh ever grand prix.
Catalan Grand Prix:
3. Roberts Jr