Lleyton Hewitt faced off against a fellow former warrior whose career has also suffered a slide, emerging with a 7-6 (7/5), 6-4 victory on Monday over Juan Carlos Ferrero in a first-round match at the Montreal Masters.
Each of them held the No. 1 ranking briefly during the peak period of their reign earlier this century.
Australia's Hewitt, ranked 21st, was playing on North American hardcourts for on the first time since March.
He said that times have changed since his prime in 2001 and 2002 when he lifted US Open and Wimbledon trophies.
"A lot more players getting better," Hewitt said. "We probably took it to another level, then Roger [Federer] has taken it to another level again."
"A lot of things have changed," he said.
Hewitt, 26, said that his run of injuries in the past season has contributed to his slide, while 17th-ranked Spaniard Ferrero has also had his worries.
"He had the chickenpox and had a few bad injuries, which were tough to come back from," Hewitt said. "He can match it with the best players."
Even the optimistic Aussie admits that Federer and No. 2 Rafael Nadal stand a huge step ahead of the chasing pack.
"They're not going to get any worse," Hewitt said. "Guys are going to have to step up to the plate, play a lot better week in and week out.
"Those guys are so good because they bring their `A' game every week," he said. "Very rarely do they have a bad match."
The Australian won a hardcourt title in Las Vegas, then lost in Indian Wells before going home injured for two months.
Hewitt is making a comeback without the presence of new coach Tony Roche, who is at home in Sydney awaiting the birth of a grandchild. Hewitt now leads Ferrero 6-3 in their career series.
Tenth seed Tomas Berdych took the week's first upset loss, and then admitted that the match-fixing drama surrounding Nikolay Davydenko was worse than any doping controversy.
The Czech, on court for the first time in five months, was beaten by Dutch qualifier Robin Haase 6-4, 7-5.
Davydenko, fifth in the world, was cited for a suspicious mid-match injury withdrawal last week in Poland.
The Association of Tennis Professionals launched an investigation after online betting on the second-round contest was halted due to a flood of US$7 million to eventual winner Martin Vassallo-Arguello of Argentina.
Davydenko quit in the third set with a foot injury. Online agency Betfair refused to pay out on the match, citing money flowing at 10 times the normal amount.
Berdych was among association players who listened at a Miami players meeting last spring as reformed former Mafia boss Michael Franzese explained the diabolical consequences of match-fixing.
"I think this is much worse ... than the doping," Berdych said.
"Imagine if you have a situation that they come to you and they give you the offer with money and tell you: `If you lose this match, you gonna get whatever,'" he said.
"It happens once, and they're gonna come again another tournament and you're going to say: `No, I don't want to do it, I'm going to play,'" he said.
"Then the problem starts," he said.
India's Sania Mirza celebrated her move into the top 30 in the world rankings on Monday with a first-round triumph over Alexsandra Woznia in the US$600,000 East West Bank Classic.
Mirza moved up a notch to No. 30 in the rankings released on Monday after reaching the quarter-finals of a tournament in San Diego last week.