In their first league matches since the first day of the month, it was visitors Malmo who began the brighter, taking a ninth-minute lead thanks to Taha Ali's first Allsvenskan goal of the season.
Mjallby finally carved out an equaliser in the 73rd minute through Elliot Stroud, but despite a late red card for Colin Rosler, the hosts could not find a winner, leaving them one point clear at the top as Malmo sit fifth, eight points off the pace.
The team one point off the top are Hammarby, who made ground thanks to a 2-0 home win over Halmstad.
Nahir Besara broke the deadlock after half an hour, before Sebastian Tounekti grabbed his second goal involvement of the game in the second half, scoring a glorious goal to put the game beyond Halmstad, who lose for the fourth time in five outings.
Hot on the heels of the top two are AIK, who returned to action in style with a 3-0 victory over IFK Goteborg.
Filip Benkovic and 16-year-old debutant Kevin Filling did the damage for the Solna side in the first half, before Johan Hove wrapped up the comfortable victory on 61 minutes as Goteborg's three-match winning run was put to the sword.
Losing further ground in the title race this week were Elfsborg - defeated by Hammarby in their final match before the break, they returned with an underwhelming goalless draw with bottom side Varnamo.
That saw Elfsborg slip to fourth, five points behind the leaders, as Varnamo remain cut adrift and winless.
Monday night's other match ended in a 1-1 draw between the two sides locked together in midtable - Djurgarden remain one point and one place above Norrkoping.
Tobias Gulliksen put the Stockholm side ahead in added time at the end of the first half, then Christoffer Nyman levelled the scores for the visitors just before the hour mark.
Elsewhere, Degerfors' first match since the somewhat surprise sacking of William Lundin ended in a 3-0 loss at home to Brommapojkarna, who leapfrog their opponents into 12th place.
Love Arrhov opened the scoring, then early second-half strikes from Anton Kurochkin and Eric Bjorkander extended Degerfors' losing run to four matches, and ended BP's own run of six defeats.
On a three-match winning run and a five-match unbeaten run are GAIS, who moved up into sixth with a 3-1 defeat of Hacken.
The Gothenburg club were 2-0 up inside 16 minutes, courtesy of Rasmus Niklasson, who scored the first and set up the second for Ibrahim Diabate. Amin Boudri made it 3-0 with a quarter of the match to go, before Isak Brusberg added a consolation for Hacken, who drop to eighth.
Only one point separates Sirius in 11th and Oster in 15th, as the latter twice came from behind to draw 2-2 at home and go five matches unbeaten.
Robbie Ure and Leo Walta twice gave Sirius the advantage in the second half, but on both occasions were pegged back by Ivan Kricak and - in the 95th minute - David Seger.
Follow the 2025 Allsvenskan throughout the summer on Flashscore.