Ukraine put their hammering at the hands of Spain behind them by outclassing a poor Saudi Arabia side.
Shevchenko scored the third for Ukraine
Ukraine were ahead inside four minutes when Mabrouk Zaid needlessly gave away a corner and Andriy Rusol bundled in.
Saudi keeper Zaid was also at fault when he slipped attempting to keep out Serhiy Rebrov's 35-yard piledriver.
Maxim Kalinichenko set up Andriy Shevchenko to head a third just after half-time and the roles were reversed for Kalinichenko to tap in a fourth.
Little went right for Ukraine on their World Cup finals debut against the Spanish.
But it was a vastly different story in Hamburg as they showed why they were the first European side to qualify for the finals.
The Saudis appeared nervous from the start, in particular Zaid, and Ukraine were not slow to take advantage.
The keeper made a hash of a goalkick to give Ukraine an early corner.
Kalinichenko curled the ball in and defender Rusol marched into the area unopposed to deflect it off his knee and through the unfortunate Zaid's legs.
Saudi Arabia seemed to struggle in the slippery conditions in Hamburg, while Ukraine found the surface to their liking with their swift, counter-attacking passing game.
Shevchenko was looking more like the striker Chelsea paid £30m for and was involved more in the opening quarter of an hour than in a statuesque 90 minutes against Spain.
Ahmed Dokhi cleared a Shevchenko effort off the line, while the former AC Milan star just failed to get on the end of a Kalinichenko pass after English referee Graham Poll had unintentionally played a part in the build-up.
The closest Saudi Arabia got to a goal was when Rusol's knee almost scored at the wrong end, but the defender will have been relieved to see his mis-hit clearance flash past the post.
Rebrov fired in a second goal shortly before the interval.
Anatoliy Tymoschuk rolled the ball into the feet of the former Spurs and West Ham forward and he was given space to turn.
Ukraine went ahead after just four minutes
He showed no hesitation in hitting a fine strike that flew into the corner, although there was more questionable goalkeeping from Zaid who slipped as he tried to get across to the shot.
Zaid's performance seemed all the more bizarre with Mohammed Al Daeyea - he of the world-record 181 caps - sitting on the bench.
Any hope of the Saudis launching another second half comeback lasted less than a minute of the second period.
Another pin-point centre from Kalinichenko saw Shevchenko open his World Cup finals account with a simple header.
Kalinichenko was denied a deserved goal when he hit the bar with a shot, but six minutes from time he put their goal difference back on level terms when he sidefooted home from a Shevchenko centre.
The win puts Ukraine's qualification hopes back on track and victory over Tunisia in their final game will ensure their progress to the knock-out stages.
Saudi Arabia will have to beat Spain to have any hope of going through, and on this performance they can now start preparing for their flight home.
Saudi Arabia: Zaid, Dokhi (Khathran 55), Tukar, Al Montashari, Sulimani, Al Ghamdi, Ameen (Mouath 55), Noor (Al Jaber 77), Khariri, Aziz, Al Kahtani.
Subs Not Used: Al Anbar, Al Bahri, Al Daeyea, Al Harthi, Al Qadi, Al Temyat, Khojah, Massad.
Booked: Dokhi, Al Ghamdi, Khariri.
Ukraine: Shovkovskiy, Nesmachniy, Rusol, Sviderskiy, Tymoschuk, Shelayev, Gusev, Rebrov (Rotan 71), Kalinichenko, Shevchenko (Milevskiy 85), Voronin (Gusin 79).
Subs Not Used: Yatsenko, Yezerskiy, Byelik, Chigrynskiy, Nazarenko, Pyatov, Shust, Vorobey.
Booked: Nesmachniy, Kalinichenko, Sviderskiy.
Goals: Rusol 4, Rebrov 36, Shevchenko 46, Kalinichenko 84.
Ref: Graham Poll (England).
Fifa man of the match: Maxim Kalinichenko.
This 4-0 win over Saudi Arabia was the first ever victory for Ukraine at a World Cup. Andri Rusol became the first ever goalscorer for the nation in the competition. Maksim Kalinichenko had two assists in this game. Beckham (England), Figo (Portugal), Mendez (Ecuador), Riquelme (Argentina) and Schweinsteiger (Germany) are the other players with two assists at the 2006 World Cup.
Ukraine have won six of the seven matches they've played this year. Apart from the 4-0 defeat against Spain, they kept a clean sheet in every other game in 2006.
Saudi Arabia's winless World Cup sequence was extended to nine matches. The last time they won a game in the tournament finals was on 29 June 1994 when they beat Belgium 1-0.
Trivia stats source: Infostrada Sports