And it seemed that Murray's new status was already having a psychological impact on his opponents, with Del Potro admitting that the Scot is a "better" player.
"These two weeks have been tough but it's a chance to win another tournament," he said.
"It will be good for me. I like playing players who are better than me. I think he (Murray) will have the pressure, but I have to play my best."
At number three in the world, Murray is already the highest-ranked Briton since the system was introduced in 1973, but this latest move breaks up the dominance that Federer and Nadal have enjoyed.
Both men were in Montreal but fell at the quarter-final stage, Federer to Tsonga and Nadal to Del Potro.
"To get past Rafa is incredible," said Murray. "Roger and Rafa have shared the one and two ranking for the last five years.
"They are so consistent and I didn't know if I was ever going to get there. Just one more to go now."
He controlled matters from the outset against Tsonga on another searingly hot day in Montreal.
Murray went into the match having dropped serve just once in the tournament and after three love games to open proceedings, he made the first breakthrough when Tsonga netted a forehand in game four.
The Frenchman was poised to hit back straight away at 0-40 in the following game but Murray managed to find some first serves to dig himself out of trouble.
That appeared to be the end of the danger for the first set as Murray moved smoothly to 5-2 but his first serve went missing when trying to close it out in game nine, and the more attack-minded Tsonga broke back with a drop volley.
I've been three for quite a while now and it's nice to make that jump, and I'll try and go one step further
However, consistency remains the problem for the Frenchman and more errors in game 10 handed Murray two set points, the second of which he took with a crunching forehand winner.
When Tsonga let a 15-40 advantage slip with more wayward shots at the start of the second set, his challenge appeared to be fading.
Murray made his move at 4-3 but Tsonga saved two break points with a brave second serve and a thumping smash, and it came down to a tie-break.
An uneven match finally hit the heights as Tsonga started the better and earned set point at 6-5, only to go for far too much on a second-serve return, before saving a first match point with a flamboyant lob-volley.
The unpredictable Frenchman was starting to look dangerous but another set point went begging with a poor drop shot and when Murray fashioned a second match point with an ace, he converted with a fierce backhand return.
And having done an admirable job all week of playing down talk of possibly overtaking Nadal in the rankings, the Scot was rightly jubilant in his moment of victory.
"It's great," Murray told BBC Radio 5 live. "I've worked really hard after Wimbledon and it's nice when you feel like the hard work is paying off. I've been three for quite a while now and it's nice to make that jump, and I'll try and go one step further.
"To jump somebody like a Nadal or a Federer is so difficult, that's why no-one's done it for five or six years. They've dominated the rankings and in my opinion they are the two best rivals ever.
"I think it's a great achievement and I'll try and stay there as long as possible."
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