Across the net from Andre Agassi stood a man with superior firepower, a 6-foot-6-inch pitching machine with an explosive fastball serve and a nasty slicing slider, too. As 22-year-old Swede Joachim Johansson kept hurling heat Agassi’s way, it was clear that the game’s master tactician was in for a long day.

In the end, patience and precision prevailed over power, as Agassi withstood a tour-record 51 aces and pulled off a remarkable 6-7(4), 7-6(5), 7-6(3), 6-4 victory Sunday evening at the Australian Open. Next up for the American is world no. 1 Roger Federer in the most anticipated match of the tournament. Federer, who defeated qualifier Marcos Baghdatis 6-2, 6-2, 7-6(4), has won 25 straight matches, the longest streak of his career. He beat Agassi in five sets during their last meeting at the 2004 U.S. Open.

“Roger offers me the opportunity to push myself more than I’ve been pushed in a long time,” Agassi said. “That’s a great feeling.”

Agassi may need a minor miracle to get past Federer in the quarterfinals on Tuesday, and perhaps something more to take his fifth Australian Open title. But whatever happens from here, his victory over Johansson will be remembered as one of the aging legend’s finest moments.

Strategically and emotionally, Agassi was perfect. He made just 13 unforced errors and impeccably timed his strokes, despite having few chances to rally and develop a rhythm. Afterwards, he said this match had fewer points consisting of three shots or more than his 1992 Wimbledon victory over Goran Ivanisevic, in which Agassi was aced 37 times.

“All I can do is try not to be overwhelmed out there,” Agassi said. “I’m worried about embarrassment when I come out there and a guy can serve 51 aces. I’m surviving.”

In the early going, Agassi looked like he would do more than survive. He won the first three games and took a 4-1 lead. Johansson had aggravated a tender hamstring in a four-hour, third round victory that ended 13-11 in the fifth set, and he did not seem eager to try to keep up with the superbly fit Agassi.

Within minutes, though, Johansson reminded Agassi of the adage about wounded giants. The Swede, not known for timid strokes, decided to go for broke. Fourteen aces and a dozen winners later, he had charged back to win the first set in a tiebreak.

To understand how tedious a task it can be to stand toe-to-toe with a heavyweight like Johansson, consider this: Johansson made 17 errors in the first set, while Agassi made none. Although the Swede doesn’t serve as fast as Andy Roddick, his height allows him to create bigger angles and higher bounces than most men on the tour. His forehand is one of the most forceful in the game and his one-handed backhand, while lacking consistency, is deadly when it finds the court. If Johansson can land his haymakers, a counter-puncher like Agassi has no margin for error.

Agassi nearly got himself knocked out cold in the second set. He won his first three service games at love but fell behind 30-40, trailing 4-3 in the set. Pulled off the court by a Johansson angle, Agassi sliced a backhand back into play. Johansson charged the net with Agassi on the run, but he gave the American too much time to load up a forehand passing shot. Agassi, who had only a narrow opening down the line, nailed a winner. Two strong serves later, he had escaped.

Agassi’s attempts to solve Johansson’s serve failed miserably. He tried to buy himself an extra fraction of a second by retreating from his usual perch along the baseline to the shadows near the back of the court. Oftentimes, he guessed where Johansson might aim and dashed over there before the Swede unloaded. Johansson was in a groove, and Agassi’s odds were long. By the middle of the second-set tiebreak, Johansson had piled up 30 aces.

“There was a good 25 times out there where I felt like I knew where it was going, was leaning that way, and if I jumped and threw my racquet, I probably wouldn’t touch it,” Agassi said of Johansson’s serve. “That doesn’t count all the other times where I was actually wrong about where he was serving.”

Yet Agassi prevailed in the tiebreak, pressuring Johansson early and forcing him to fend off two set points. Johansson got one back by clobbering a backhand winner, but he made a forehand error to vault Agassi back into the match.

From there, Johansson’s energy began to wane. He fought his way into another tiebreak, only to come up short by four points. And even though he scored an early break in the fourth set for a 2-0 lead, Agassi, after a day of throwing nothing but jabs, had his opponent lined up for the kill. He broke Johansson in the next game despite three aces, held quickly, and then broke again. When it was over, he jogged to the net and clenched his fist, his only display of emotion the entire match.

Johansson’s 51 aces surpassed Richard Krajicek’s record of 49, set in five sets at the 1999 U.S. Open (Krajicek also lost). Agassi has had his part in another ace record, as well: Australia’s Mark Philippoussis aced Agassi 46 times at the 2003 Wimbledon. Philippoussis won that match.

***

SERENA MUDDLES THROUGH

Shortly after Johansson blasted his way into the record books, Russia’s Nadia Petrova seemed intent on setting a mark for serving futility in a 6-1, 3-6, 6-3 loss to Serena Williams. Petrova double-faulted five times in a first set that had all the makings of a blowout. But as the match wore on, Williams was hardly any better. Her inconsistent first serve regularly betrayed her, and she began talking to herself as she lost her grip on the second set.

Though Williams came away with a win, she looked mortal. She’s still not covering the court like she did in years past, and her once-lethal serve is inconsistent. If not for Amelie Mauresmo’s history of Grand Slam failure, it would be hard to call Williams the favorite in their upcoming quarterfinal match.

***

DAVENPORT SHINES AS RUSSIAN WOMEN FALL

In early Monday action, Lindsay Davenport played her most convincing match of the tournament, drubbing 13-seed Karolina Sprem, 6-2, 6-2. Davenport hit a few rough patches on her service games, but she struck the ball cleanly from both sides.

Meanwhile, third seed Anastasia Myskina became the second top woman to fall Monday, spraying 45 unforced errors in a 6-4, 6-2 loss to Nathalie Dechy.No.6-seeded Elena Dementieva fell 6-7(6), 7-6(4), 6-2 to Patty Schnyder in a match marred by errors – 116 in all – and two long bathroom breaks that smacked of gamesmanship.

On the men’s side, Andy Roddick dispatched Philipp Kohlschreiber, 6-3, 7-6(6), 6-1. Kohlschreiber, ranked 102nd in the world, was the last of a handful of unheralded men who made an impression in Melbourne this year, from American qualifier Bobby Reynolds to Belgium’s Olivier Rochus, who put up a valiant fight against Marat Safin in losing 4-6, 7-6(1), 7-6(5), 7-6(2).