Roger Federer can win the Davis Cup for Switzerland for the first time on Sunday when he plays in the first of the reverse singles against French number one Jo-Wilfried Tsonga.
The 17-time Grand Slam champion teamed up with Stan Wawrinka on Saturday to defeat Julien Benneteau and Richard Gasquet in straight sets in a vital doubles clash in Lille.
That put Switzerland 2-1 ahead and on the cusp of what would be one of the country's greatest ever sporting achievements. A win for Federer over Tsonga would seal the deal.
It would also be a superb consecration for him, late in his career, adding Davis Cup glory to a full set of Grand Slam titles and Olympic gold, albeit in the doubles.
It was quite a different Federer that was on display on Saturday compared to Friday when he lost dismally in straight sets to Gael Monfils.
Inspired by the top-class tennis produced by partner Wawrinka, Federer visibly grew in confidence and he confidently served out to love to clinch the win.
There remains the question-mark over the state of his back which crippled him at the ATP World Tour finals in London last weekend.
Asked if he felt 100% fit he replied: "Yeah, I mean, that's my mindset right now. Honestly, it's like the last question I'll answer about my back now.
"I'm fine now. I understand you want to know everything about it. But I know as much as you do.
"I've been very open and honest. For me it's just about now whatever it feels like, I feel like I am at 100%. I'll give it 100%. That's all I can do right now."
Federer has an 11-5 winning record against Monfils, but he lost their last encounter in straight sets in the Canada Masters in August and they have never before played in the Davis Cup.
Adding more intrigue to the story is that there are also persistent injury rumours surrounding Tsonga.
He was troubled by a painful right forearm at the French training camp in Bordeaux and did not at all look comfortable on Friday when he lost in four sets to Wawrinka.
Despite that loss, the expectation was that Tsonga would partner Gasquet in the doubles, and there was
general surprise when it was announced that Benneteau would play instead.
Tsonga was then seen to shed a tear or two during an emtional on-court ceremony preceding the doubles, fuelling talk that he was struggling.
If he was, the French camp were giving little away.
"Imagine if there was something, I wouldn't tell you anyway," said team captain Arnaud Clement. "Of course, I can just say that Jo rested today for some reasons and there will be no problems tomorrow."
If Tsonga does win it will all go down to the wire in the last match against Wawrinka and Monfils, the two outstanding players so far in this Davis Cup final.
The two have only played each other four times and are level at 2-2. Their last encounter was in the last 32 of the Australian Open in 2011 when Wawrinka won in straight sets.
"I feel great with my game," said Wawrinka after the doubles win.
"As I say, it was important to get some confidence. I feel that I'm playing well, good tennis. I'm great on the court, a lot of confidence.
"You know, I'm here to go for the win, not to expect something else. I need to try everything I have in my racquet to win those matches."