Crewe Alexandra 0 Doncaster Rovers 2: Clinical Doncaster looking very hard to stop as Wembley looms into view

Doncaster Rovers are on a roll and a half, Crewe Alexandra are not.

Grant McCann's side steamrollered into the League Two play-offs on the back of 12 games unbeaten, the middle 10 all won, whereas Crewe lost their last two Gresty Road games 3-0 and needed a late equaliser at 22nd-placed Colchester United to ensure they did not go into the bonus round of the campaign on the back of three straight defeats.

The play-offs do funny things, and you would never have known it by the way both teams started their semi-final first leg, but when Doncaster got a chance, they took it, and you could see the contrasting confidence of the teams from there.

Both knew who was going to win.

At 2-0, with goals from Luke Molyneux and Harrison Biggins, Doncaster's lead halfway through this semi-final tie is far from impregnable and it might have been thinner still, Chris Long flicking a Zac Williams header wide at a corner won when Rio Adebisi nearly embarrassed Thimothee Lo-Tutala with a long-range effort.

The away fans who filled the Ice Cream Van Stand with a mixture of red-and-white home and blue-and-white away hopped shirts waited until the sixth added minute before they dared started que sera-ing but with Friday's game due to be played in front of an excited Eco-Power Stadium – more than 9,000 tickets had been sold before the first leg kicked off – you would be a brave man to bet against them going to Wembley on May 19.

Crewe actually had the better of the opening half-hour, Rovers struggling to get their foot on the ball, and to deal with Mickey Demetriou's formidable long throw. By the end that all felt like a distant memory.

Lo-Tutala, booed relentlessly by the home fans after having a red card which would have seen him suspended for the trip across the Pennines, showed his irritation when he reacted to a dig from Elliott Nevitt after dropping, then regathering a Matus Holicek cross.

But in the 34th minute, the Railwaymen gave Doncaster a glimmer and on this form, it is all the need.

The outstanding Matthew Craig won the ball high up, Hakeeb Adelakun played the Tottenham Hotspur loanee in at the byline and Molyneux, into the centre-forward position off the right wing, finished the pull-back expertly.

The chants for Molyneux soon made way for cries of "Super Grant McCann". That was no disrespect to the goalscoring winger, just an appreciation of the architect of Rovers' incredible run from 22nd at the start of February to fifth at the end of April.

It might have been 2-0 before half-time, Adelakun also drifting off his line into the No 9 position to win the ball and helping out to the left, where Biggins had intelligently filled the gap. The fit-again midfielder's shot clipped the crossbar.

It had not been on the cards.

Adelakun almost had a very good chance in the fifth minute when his footwork put Lewis Billington on his backside, only for the defender to recover brilliantly.

Generally, though, the game was played more at the other end, headers from Nevitt and Rio Adebisi forcing saves, and Tom Anderson needing a very good block after Shilow Tracey raced past his central defensive partner Richard Wood, his head bandaged after his latest stitches. It does not really count as a proper Doncaster game if one of the veteran centre-backs does not have something broken or cut.

When Wood headed a Demetriou throw-in to Ryan Cooney, he hit his shot into the blue-and-white hooped crowd and appealed in vain for a handball. A Joel Tabiner shot had the sting taken out of it.

But if there is anyone good at clearing their collective heads and getting on with it, it is the club who in February decided they were going to rest the table, and see if they could come top over the last 18. They finished 17 points clear despite second-placed Wrexham playing 19 matches in that time.

So they eased their way back into the game and took their chances either side of the break.

The second was offered up when Demetriou failed to clear a hopeful header forward by Wood.

Ironside latched onto it and when he pulled the ball back, Biggins had run from midfield to sweep the ball in from 10 yards. It was only 48 minutes into what will be at least a 180-minute contest but it felt psychologically significant.

Biggins came off injured quickly afterwards.

Max Stryjek had to make a good save to stop Owen Bailey making it three, volleying after a penetrating run from James Maxwell.

It kept the tie alive, albeit nowhere near as delicately-poised as it would have been had Long found the net in the 80th minute.

That said, Stryjek needed a sharp save to stop Molyneux beating him at his near post three minutes before the end of regulation time.

Doncaster, though, have so much momentum they look hard to stop. The 99s are on them.

Crewe Alexandra: Stryjek; Billington, Demetriou, Williams; Cooney (Thomas 56), Adebisi, Tabiner (Long 68), Austerfield (Baker-Richardson 56), Holícek; Nevitt, Tracey (Rowe 10).

Unused substitutes: Turns, Kirk, Lenarcik.

Doncaster Rovers: Lo-Tutala; Sterry, Anderson, Wood, Maxwell; Bailey, Craig (Broadbent 84); Molyneux, Biggins (Rowe 50), Adelakun (Hurst 75); Ironside.

Unused substitutes: Olowu, Jones,Westbrooke, Waters.

Referee: SS Gill (West London).