Ronald Koeman hailed Fraser Forster as one of the best goalkeepers in Europe after seeing him repel a host of Arsenal chances in Southampton's 0-0 draw at the Emirates on Tuesday.
Forster only returned from a nine-month injury layoff in January, but showed he is back to his best already by making a string of impressive saves against Arsenal.
The Gunners dominated most of the game, and Koeman said he has never seen a team create more chances against his side in his two-year stint at the club.
"Then you need a goalkeeper that is magic, and he was magical tonight," Koeman said. "That is maybe what I need to explain about what happened today."
Forster stopped Mesut Ozil twice in the first half, including a one-handed save from point-blank range, and then denied Olivier Giroud, Alexis Sanchez and Theo Walcott on numerous occasions in the second half.
Asked where he rates Forster among goalkeepers, Koeman replied: "He is one of the best goalkeepers in the Premier League and maybe he is one of the best in Europe."
While Arsene Wenger lamented what he called "very bad" finishing by his players, Koeman heaped all the credit on Forster for being able to play at a top level so soon after his injury comeback. Forster was sidelined since last March with a serious knee injury.
"He was nine months out. Maybe we had to force a little bit his coming back because Maarten Stekelenburg was injured. If he was not injured maybe we would have waited one or two weeks more," Koeman said.
"We know normally if you are nine months out you need rhythm, game minutes. But from the start he is [back to his best]. And that's unbelievable."
Koeman's team have had an inconsistent season, but this was the latest good result against a top team. Southampton beat Arsenal 4-0 at home and have won at Manchester United and Chelsea this season.
"It's now a fourth clean sheet in a row and that is giving confidence to the players," Koeman said.
The only downside was that new signing Charlie Austin missed the game after picking up a knock in training. However, Koeman downplayed the injury and said it was just "too risky" to play the forward.
"It's not a serious injury, and normally he will be available for the weekend," Koeman said.